DEVELOPMENT OF INVERTEBRATE ASSEMBLAGES ON ARTIFICIAL REEF CONES OFF SOUTH CAROLINA: COMPARISON TO AN ADJACENT HARD-BOTTOM HABITAT

A thesis submitted in partial fulfillment of the requirements for the degree

MASTER OF SCIENCE

in

ENVIRONMENTAL STUDIES

by

DANY E. BURGESS MAY 2008

at

THE GRADUATE SCHOOL AT THE COLLEGE OF CHARLESTON

Approved by:

Dr. Elizabeth Wenner, Thesis Advisor

Dr. Jeff Hyland

Dr. Rachael King

Mr. Robert Martore

Dr. Amy T. McCandless, Dean of Graduate Studies ACKNOWLEGDEMENTS

First and foremost, I would like to thank my committee members, Elizabeth Wenner (advisor), Rachael King, Jeff Hyland, and Bob Martore for their time, guidance, and patience throughout the course of this project. Special thanks to Bob Martore and the Artificial Reef Program for providing financial support for as long as I needed it; to the staff of the SERTC lab for generously sharing their workspace and supplies; to Jessica Boynton for GIS assistance; and to Mike Arendt and Stephen Blackmore for database management and moral support.

In addition, I would like to thank the talented scientists and fellow graduate students who dedicated many uncompensated hours to helping me collect and identify thousands of critters: David Knott, Susan DeVictor, Dale Calder, Dave Pawson, Richard Heard, Joe Cowan, Nadia Meyers, Ian Moody, Daryl Stubbs, Bryan Frasier, Chris Bradshaw, and especially Rachael King. Thanks also to the crews of the R/V Palmetto and the R/V Silver Crescent for providing field transportation, to the MARMAP program for the use of their electronic balance, and to the infinitely helpful and accommodating faculty and staff of the MES program.

Finally, I would like to dedicate the completion of this thesis to my family, particularly my parents, David and Kathy Burgess, who have always believed that I could be whatever I wanted; to my sister, who never stopped speaking to me even when I truly deserved it; also to my amazing grandparents, Cynthia and Joseph Miller, who have been dragged to more ceremonies and backyard tea parties than they probably care to count, and always kept smiling. Their support over the years, both emotional and financial, has kept me on the path to achieving my dreams. Their lessons – mainly to respect and care for the environment and all its creatures – had a hand in shaping those dreams. I love you guys.

Thank you all so much for sharing this experience with me. I would not have been able to do it without you.

ii TABLE OF CONTENTS

PAGE LIST OF FIGURES ...... iv

LIST OF TABLES...... vi

ABSTRACT...... 1

INTRODUCTION ...... 2 Objectives...... 10

MATERIALS AND METHODS...... 12 Study Sites ...... 12 Preliminary Site Visit...... 14 Field Sampling...... 14 Laboratory Processing of Scraped Samples...... 15 Analysis of Digital Photographs and Archived Video Data ...... 17 Statistical Analyses – Univariate Methods ...... 18 Statistical Analyses – Multivariate Methods...... 20

RESULTS ...... 22 Description of Study Sites ...... 22 Species Number, Species Richness, Abundance, and Biomass...... 23 Diversity Indices ...... 24 Species Composition – Artificial Reefs...... 24 Species Composition – Natural Reef...... 26 Similarity Indices ...... 27

DISCUSSION...... 31 Community Composition...... 31 Community Indices...... 34 Age of Artificial Reefs ...... 36 Influence of Other Factors...... 39 Implications for Fisheries Management ...... 40 Future Directions...... 42

CONCLUSIONS...... 44

LITERATURE CITED ...... 46

FIGURES...... 55

TABLES ...... 81

APPENDICES ...... 96

iii LIST OF FIGURES

FIGURE PAGE

1.) Map of study locations, showing approximate position of artificial and natural reefs to the Charleston peninsula...... 56

2.) Configuration of artificial and natural reefs ...... 57

3.) Dimensions of the Swiss Cone ...... 58

4.) Digital photograph of a preserved scrape sample collected from Julian’s Ledge station A during August 2005...... 59

5.) Digital photographs of ossicles, viewed with a compound microscope, and corresponding sea cucumber specimens...... 60

6.) Digital photographs of scrape samples collected from Julian’s Ledge stations during 2005...... 61

7.) Digital photographs of scrape samples collected from Area 53 during 2005 ...... 62

8.) Digital photographs of scrape samples collected from Area 51 during 2005 ...... 63

9 a-b.) a.) Mean number of species (s) per 15 cm² quadrat for each reef site, and b.) total number of species in all scrape samples for each reef site...... 64

10.) Median species richness (SR) per 15 cm² quadrat for Area 53, Area 51, and Julian’s Ledge...... 65

11 a-b.) a.) Median number of individuals (n) per 15 cm² quadrat for each reef site, and b.) total number of individuals in all scrape samples for each reef site...... 66

12.) Mean biomass per 15 cm² quadrat for Area 53, Area 51, and Julian’s Ledge ...... 67

13 a-b.) Median values of a.) diversity (H´) and b.) evenness (J´) per 15 cm² quadrat for Area 53, Area 51, and Julian’s Ledge...... 68

14.) Percent contribution of major taxa (≥1%) to the total abundance of Area 53 ...... 69

iv

15.) Percent contribution of major enumerated taxa (≥1%) to the total abundance of Area 51 ...... 70

16.) Percent contribution of major enumerated taxa (≥1%) to the total abundance of Julian’s Ledge...... 71

17.) Percent contribution of major sessile taxa to the total number of sessile species from Area 53 ...... 72

18.) Percent contribution of major sessile taxa to the total number of sessile species from Area 51 ...... 73

19.) Percent contribution of major sessile taxa to the total number of sessile species from Julian’s Ledge...... 74

20 a-b.) Dorsal views of a.) female and b.) male specimens of Limnotheres nasutus, collected from the northeast and northwest stations of Area 53...... 75

21.) Normal Canberra Metric cluster dendrogram (replicates pooled by sum of species abundance)...... 76

22.) Inverse Canberra Metric cluster dendrogram (replicates pooled by sum of species abundance)...... 77

23.) Normal Jaccard similarity dendrogram (replicates pooled by presence/absence)...... 78

24.) Inverse Jaccard similarity dendrogram (replicates pooled by presence/absence)...... 79

25 a-b.) a.) Correlation between abundance of Syllis and Haplosyllis sp. and diversity (H’) in samples collected from Area 51 in 2005, and b.) abundance of Syllis and Haplosyllis sp. in Area 51 collections, noting presence/absence of the sponge Lissodendoryx sp ...... 80

v LIST OF TABLES

TABLE PAGE

1.) Collection dates and hydrologic parameter measurements for artificial and natural reef stations visited in 2005 and 2006 ...... 82

2.) Community structure values per 15 cm² for stations sampled at the younger artificial reef (A53), older artificial reef (A51), and Julian’s Ledge natural reef in 2005 ...... 83

3.) Summary of statistical analyses of community structure values...... 84

4.) Ranking of most abundant species overall (> 1%)...... 85

5.) Rank by abundance of the top 25 most abundant species in samples collected from Area 53 and Area 51 in 2005...... 86

6.) Rank by abundance of the top 25 most abundant species collected from Julian’s Ledge in 2005...... 87

7.) Overall rank by frequency of occurrence (%) of major sessile taxa occurring in 10 or more samples collected from Area 53, Area 51, and Julian’s Ledge in 2005 ...... 88

8.) Rank by frequency of occurrence (%) of the top 25 most frequently occurring sessile species in samples collected from Area 53 and Area 51 during 2005...... 89

9.) Rank by frequency of occurrence (%) of the top 25 most frequently occurring sessile species in samples collected from Julian’s Ledge during 2005...... 90

10.) Species groups resulting from inverse Canberra metric cluster analysis...... 91

11.) Species groups resulting from inverse Jaccard similarity analysis...... 92

12.) Results of Components of Variance analysis...... 95

vi ABSTRACT

DEVELOPMENT OF INVERTEBRATE ASSEMBLAGES ON ARTIFICIAL REEF CONES OFF SOUTH CAROLINA: COMPARISON TO AN ADJACENT HARD-BOTTOM HABITAT

A thesis submitted in partial fulfillment of the requirements for the degree

MASTER OF SCIENCE

in

ENVIRONMENTAL STUDIES

by

DANY E. BURGESS

MAY 2008

at

THE GRADUATE SCHOOL OF THE COLLEGE OF CHARLESTON

Artificial reefs are often used to increase the amount of hard-bottom habitat in otherwise sandy areas, including parts of South Carolina’s continental shelf. In 1997 and 2003, the SCDNR deployed two designed concrete reefs off the coast of Charleston, SC, for use in fishing experiments. This study was conducted to assess the development of epifaunal invertebrate assemblages on both the younger (“Area 53” – 2 years old) and older (“Area 51” – 8 years old) reefs. Each artificial reef was also compared to an adjacent natural reef, “Julian’s Ledge”, in an attempt to determine whether designed structures can form habitats that resemble natural hard-bottom areas over time. Macrofaunal invertebrates from each of the three reef sites were collected during Spring/Summer 2005. A total of 24,940 individuals were found, comprising at least 384 motile and sessile species. Cluster analysis revealed that species composition between reef sites was distinct, with Julian’s Ledge displaying higher species number and diversity; however, evidence for convergence over time included a large group of species common to all three sites, and a higher level of similarity between Julian’s Ledge and Area 51 than between Julian’s Ledge and Area 53. Additional sampling at a later time period could help to elucidate whether these trends may be attributed to reef age, or other environmental variables. This study provided the first catalogue of invertebrate data for any of South Carolina’s designed experimental artificial reefs.

1

INTRODUCTION

In the waters of the South Atlantic Bight (defined here as the region between Cape

Hatteras, North Carolina and Cape Canaveral, Florida; Struhsaker 1969), only a small percentage of the sea floor is hard-bottom habitat; in South Carolina alone, it is estimated that rocky ledges and outcroppings, which support more than 70% of the region’s offshore pelagic and reef fisheries, make up only 10-20% of the bottom substrate of the continental shelf (Van Dolah et al. 1994). These formations, originally referred to as

‘live-bottom’ by Cummins et al. (1962), are characterized by a variety of attached sessile invertebrates and diverse tropical and subtropical fish assemblages (Wenner et al. 1983).

The majority of seafloor habitat in the South Atlantic Bight is a smooth, sandy substrate where productivity is driven by sand-dwelling infauna rather than by reef-associated fauna (Hyland et al. 2006). Artificial reefs composed of man-made materials have been used as fisheries management strategies in these predominantly sand sea floor habitats, increasing the amount of hard substratum that serves as a base for new reef communities.

Artificial reefs were defined by the European Artificial Reef Research Network

(EARRN; see Jensen 1997) as “submerged structures placed on the sea bed deliberately, to mimic some characteristics of natural reefs.” Since the deployment of the first artificial reef in Japan in the 1700’s (Ino 1974), the primary goal – to increase fishing success – has remained relatively unchanged (Ambrose and Swarbrick 1989). In the face of the recent decline of harvests for many of the world’s fisheries, reef project managers

2 have begun to consider artificial reefs important tools for the enhancement of resource production. In many cases, however, an artificial reef will quickly develop a fish

community with similar or greater abundance and diversity than the surrounding natural

habitat (review by Bohnsack and Sutherland 1985; Bortone et al. 1994; Rilov and

Benayahu 2000; Arena et al. 2007), giving rise to the debate on whether artificial reefs actually increase fish production, or merely attract and concentrate existing fish stocks so that they can be more easily exploited (Alevizon and Gorham 1989; Lindberg 1997;

Pickering and Whitmarsh 1997; Bortone 1998; review by Svane and Petersen 2001).

Also controversial are the impacts that physical and biological changes, imposed by the placement of made-made structures, can have on existing infaunal populations (Davis et al. 1982; Ambrose and Anderson 1990; Danovaro et al. 2002). In order to shed light on the attraction-production debate, minimize harm to the receiving environment, and continue to improve understanding of artificial reef function, researchers have suggested more thorough planning, monitoring, and experimental efforts associated with current and future reef projects (Bohnsack and Sutherland 1985; Carter et al. 1985; Bohnsack

1989; Seaman et al. 1989; Pickering and Whitmarsh 1997; Baine 2001; Miller 2002).

One component of artificial reefs that has benefited from research is the type of structure that makes up the reefs. Historically, this has varied based on geographic

region. In the United States, much emphasis has been placed on dumped waste or scrap

materials including tires, old bridges, subway cars, and sunken vessels. Often referred to

as “materials of opportunity,” mostly due to their availability and cost-effectiveness (Bell

et al. 1989; Pickering et al. 1998), these types of materials may be structurally unstable or

have the potential for leaching contaminants into the water. Although many of these

3 types of reefs are still in use, increased funding in the past few decades, due largely to public support, has allowed for the advancement of reef-building technology, and has lead to the development of fabricated or designed reefs (Bell et al. 1989; McGurrin et al.

1989; Kellison and Sedberry 1998). These reefs integrate both biological and engineering principles by using informed design in an effort to fulfill the life history requirements of target species (Seaman and Jensen 2000). Prefabricated reef modules were introduced into the United States in the early 1980s, and are typically constructed from marine cement with a pH similar to that of seawater. The durability and structural options provided by these modules make them a more effective way to simulate the natural limestone outcroppings, which constitute much of the hard bottom habitat in the

South Atlantic Bight region, without the environmental consequences associated with many types of industrial wastes and secondary-use materials (Bell et al. 1989;

Fitzhardinge and Bailey-Brock 1989; AGSMFC 2004).

After deployment, each new reef unit undergoes a successional process involving the formation of a bacterial film (which conditions the substrate for further colonization) and the recruitment of a variety of algal species and invertebrates that account for a large percentage of the reef’s productivity (Wahl 1989; Palmer-Zwahlen and Aseltine 1994).

These fouling assemblages often include, but are not limited to, barnacles, octocorals, hydroids, bryozoans, tunicates, and sponges, along with a suite of motile fauna that utilize the food and habitat provided by stationary organisms (Wendt et al. 1989).

Epifaunal communities are important components of successful artificial reefs because they enhance the stability and aesthetic appearance of reef structures, making them more suitable for recreational purposes - which, in turn, helps relieve natural habitats of these

4 pressures (Leeworthy et al 2006). Large benthic suspension feeders can also modify the

flux of food, larvae, and sediment deposition around a reef (Eckman 1983), and provide

refuges for both predators and prey (Thrush and Dayton 2002). Invertebrates also

provide food and habitat for both juvenile and adult fish, and often dictate the total

biomass and types of fish assemblages that a reef can support (Hueckel and Stayton 1982;

Palmer-Zwahlen and Aseltine 1994; Relini et al. 1994).

The actual numbers and types of invertebrates that ultimately colonize an artificial

reef surface may be dictated by many factors. Natural reefs constitute an important

source of larvae and spores of epibenthic organisms; therefore, proximity to natural

habitats may affect the composition of communities that subsequently settle on artificial

reefs (Van Dolah et al. 1988; review by Svane and Petersen 2001). This type of

recruitment is a function of large-scale hydrodynamic variations that include water depth,

temperature, and current. Because recruitment is seasonal in temperate regions, the

season in which a reef is deployed may also greatly affect the number and types of larvae

that colonize it (review by Svane and Petersen 2001). Researchers have cited

composition and texture of the substratum, habitat complexity and stability, and water

clarity as additional reasons why invertebrate communities on artificial reefs may

develop differently than their natural counterparts (Pamintuan et al 1994; Connell and

Glasby 1999; Badalamenti et al. 2002; Perkol-Finkel and Benayahu 2005). Orientation

of the substrate has proven to be another important factor, as vertical surfaces tend to show greater species abundance, percent cover, and biomass than horizontal surfaces

(Baynes and Szmant 1989; Wendt et al. 1989; Ponti et al. 2002; Knott et al. 2004).

5 For artificial reefs, upward trends in invertebrate biomass and species diversity have

been shown to continue for several years (Fager 1971; Van Dolah et al. 1988; Relini et al.

1994) or for as many as 10-15 years after deployment (Aseltine-Neilson et al. 1999;

Perkol-Finkel and Benayahu 2005). During this developmental period, their fouling

assemblages may remain distinct from natural surroundings. Even after an epifaunal

community is considered to be in equilibrium, biological interactions such as competition

and predation, localized physical disturbances, and seasonal fluctuations may continually

change what species are dominant (Pamintuan et al. 1994; Osman and Whitlatch 1998).

These processes are crucial for maintaining diversity and species richness and preventing

homogenization or monocultures, because space is often a limiting factor on hard

substrata (Levin and Paine 1974).

Although the dynamic nature of fouling assemblages on artificial substrata suggests

that they will presumably display greater variability than those on natural reefs, it also appears that artificial habitats function similarly to natural ones in many respects, and

may even converge with them over time. Wendt et al. (1989) compared five similar

artificial reefs ranging from 3.5 to 10 years in age, and found that there was a group of

species common to all of them - evidence of a “stable” or “climax” benthic community

being achieved after a certain period of time. They also noted that many of the same

types of organisms were found on nearby natural reefs. This parallels the pattern

observed in the successional development of invertebrate assemblages by other artificial

reef researchers, leading them to conclude that the potential exists for imitating adjacent

natural communities (Hueckel and Buckley 1987; Jensen et al. 1994).

6 In 2006, Perkol-Finkel et al. examined a 119-year-old shipwreck in the Red Sea and

found that, given sufficient time, an artificial reef’s communities can become almost

indistinguishable from those of a nearby natural reef, provided that the two habitats offer

similar structural features. This was supported by the findings of a 5-year monitoring study in Miami-Dade County, Florida. An artificial mitigation reef, structurally designed to mimic local low-relief carbonate ridges that had been damaged by a beach renourishment project, developed benthic assemblages that exhibited a “high level of similarity to the natural reef in species composition and relative species representation”, with similarity increasing significantly during the study period (Thanner et al. 2006).

The results of these studies emphasize the importance of using an experimental approach

to standardize hydrological conditions, reef size, structure, age, or isolation when

comparing natural and artificial substrata (Bohnsack and Sutherland 1985; Carr and

Hixon 1997; Perkol-Finkel and Benayahu 2007). In other studies, observed differences

between the invertebrate communities on natural reefs and those on urban structures or

“unplanned” reefs such as pier pilings (Connell and Glasby 1999; Glasby 1999; Connell

2000, 2001; Perkol-Finkel and Benayahu 2004) have been attributed to lack of control for

the above mechanisms, now known to influence reef recruitment and colonization.

Artificial reefs have been the subject of extensive scrutiny and research, and fishery

managers have expressed a desire to better understand differences among reef

populations and communities, including those on natural reefs, in order to enhance the

productivity of reef resources (Steimle and Meier 1997.) As yet, however, relatively little

is known about their ecology (review by Bohnsack and Sutherland 1985). Part of the

problem is that past artificial reef research has focused largely on the dynamics of fish

7 populations and ignored the effects of fouling development and function (Fitzhardinge and Bailey-Brock 1989; Relini et al. 1994), despite direct evidence of links between the two ecosystems. Contemporaneous comparison with nearby natural reefs is also crucial for evaluating the ‘performance’ of an artificial reef (Carr and Hixon 1997; review by

Svane and Petersen 2001); however, only a few long-term studies (greater than 5 years) have been conducted that compare artificial substrata to its natural counterparts, and the majority of these have been conducted in tropical areas, where growth of stony corals is the main concern (Thanner et al. 2006; Perkol-Finkel and Benayahu 2004, 2007). In the

South Atlantic Bight, researchers have used fouling plates (Van Dolah et al. 1988) or looked at scrap reefs such as sunken vessels (Wendt et al. 1989), but designed reefs in this area present an alternate substrate, in terms of size, shape, and material, which may be governed by a completely different set of physical and biological benefits and constraints.

The Artificial Reef Program of the South Carolina Department of Natural Resources has made efforts to address the deficit of designed reef data. In the last decade, two experimental reefs made up of hollow concrete modules were constructed and deployed off the coast of Charleston, S.C. These modules are cone-shaped, moderately rugose, and include large holes to increase habitat complexity for invertebrates and fish (see Figure

3). Originally deployed for the purpose of researching their potential as marine protected areas (MPAs), the coordinates for these reefs remain undisclosed to the public. “Area

53” is the younger of the two artificial sites; it was deployed in April 2003 and was approximately two years old at the time of this study. “Area 51” was deployed in May

1997, and was approximately eight years old. Originally, Area 51 was used for fishing

8 experiments; the southeast and southwest corners were set up as an unfished reserve,

while the northeast and northwest corners were experimentally fished with hook and line

and baited traps. Fishing experiments at Area 51 ceased in 2002. Fish tagging and video

monitoring studies are still conducted regularly at Areas 51 and 53, but as yet, there have

been no monitoring efforts associated with the development of invertebrate assemblages

on these reefs.

While it is clear that enhancement of fish populations for recreational and commercial

use remains the primary goal of today’s artificial reef programs, objectives of reef

establishment have expanded to include relieving natural habitats of pressures from the

fishing and tourism industries (Seaman et al. 1989), as well as the rehabilitation and

restoration of disturbed natural reef systems (Pickering et al. 1998; review by Svane and

Petersen 2001). Such disturbances may be due to severe weather events, but more often,

are the result of damage caused by human economic developments in coastal areas. In

the Maldives, the destructive fishing practice of coral mining has reduced many reefs to

rubble, resulting in a loss of coral cover and fish diversity. Natural recovery time for these reefs can span decades, so artificial reefs have been used to restore reef fish populations and stimulate the recruitment of new coral colonies (Clark and Edwards

1999). In the South Atlantic Bight, ship groundings and increased fishing pressures - specifically, the use of bottom-fishing techniques such as trawling - may also threaten the structural integrity and species assemblages of hard bottom and coral reefs. Reviews of numerous studies conducted over a wide range of geographic regions have documented measurable impacts to the seafloor as a result of bottom-fishing, including decreased biodiversity and habitat complexity, and homogenization of the substrata (Auster and

9 Langton 1998; Collie et al. 2000; Veale et al. 2000; Thrush and Dayton 2002). Little is known about the recovery time of these systems, and much depends on how often the disturbance occurs (i.e., whether the effects are short-term or chronic). Although effects of chronic trawling on hard-bottom areas are not well documented, mobile bottom-fishing gear has been shown to damage or remove large epifaunal organisms after even a single use (Van Dolah et al. 1987). Dredging for beach renourishment projects and navigation channels has also been labeled as one of the most harmful human activities to hard bottom habitat, causing dislocation of live rock and corals, and stress to sessile invertebrates from elevated levels of sedimentation and turbidity (SAFMC 1998b). Some researchers believe that concrete reef structures may have the potential to support epifaunal communities similar to those on natural subtropical reefs, and if so, they may prove to be a useful tool in the restoration of portions of those reefs that have been damaged or denuded as a result of anthropogenic activities.

Objectives

The main purpose of this study was to determine whether or not invertebrate communities that colonize South Carolina’s designed artificial reefs become similar to those found on natural hard-bottom reefs over time. Specific objectives were to: 1.) assess similarities and differences in the structure and composition of benthic invertebrate communities on a younger (Area 53) and older (Area 51) artificial reef, 2.) compare each of these to an adjacent natural reef, and 3.) compile invertebrate species lists for Area 53,

Area 51, and the natural reef habitat. The following was the main hypothesis tested:

10 H0: There are no major differences in benthic epifaunal community structure and selected indices (number of species, species richness, abundance, biomass, species diversity, and species evenness) among a 2-year-old designed artificial reef (Area 53), an 8-year-old designed artificial reef (Area 51), and an adjacent natural reef (“Julian’s Ledge”).

11

MATERIALS AND METHODS

Study Sites

The two artificial reef sites sampled in this study (Area 53 and Area 51) are located at

undisclosed coordinates approximately 30 miles off the coast of Charleston, SC (Figure

1). Their depths are comparable (21 and 30m, respectively) and both are located in

relatively close proximity to a 25-m-deep natural reef called “Julian’s Ledge”. Julian’s

Ledge (32 32.986 N - 079 21.608 W) is part of “The Gardens”, a moderate-relief hard-

bottom area about 26 miles offshore of Charleston. The three sites form a triangular

shape, with distances between each site ranging from 5 to 13 miles (Figure 2).

The two artificial reefs are each set up in a 2.4 km² configuration, with 100 reef cones placed randomly at each corner. The orientation of the units was not altered after deployment, and many are situated on their sides or upside down, and some are broken

into fragments. The four corners of each artificial reef area are separated by 1.5 nautical

miles of sand bottom, and were thus treated as four smaller “patch” reefs. The cones

(Figure 3) that make up these patches are a variation on the “Swiss Cone” designed by

Stevens Towing Company in Yonge’s Island, SC (Robert Martore, personal

communication).

12 Preliminary Site Visit

A preliminary visit to the artificial sites took place on November 2-4, 2004. Digital photographs and video clips were taken of cones on all corners of Area 53, and of the southeast and southwest corners of Area 51. Photographic data taken on this preliminary trip was not analyzed during the course of this study but was used to develop sampling techniques, and to assist with sampling design.

Field Sampling

Field sampling consisted of a combination of underwater digital photography and scrape sampling. The sampling plan for this study was a multiple nested design, with fixed treatments of artificial reef (young), artificial reef (old,) and natural reef. For each treatment, four stations (i.e., the four corners of each artificial reef area, and stations A through D on Julian’s Ledge; Figure 2) were sampled for six replicates each. Thus, the number of samples resulting from this design was 24 from each reef site, for a total of 72.

A single collection trip was planned for each reef site; however, sampling of Area 53 began on April 21st, 2005, and required an additional sampling day on May 10th, 2005, as well as a trip to the northeast and northwest corners in April 2006, in order to make up for insufficient material collected from these stations (see further explanation below).

Sampling at Area 51 was conducted on July 13th, 2005, and Julian’s Ledge sampling was conducted on August 10th, 2005.

Sampling time was limited due to safe diving practices. Thus, for reef cones at Area

53 and Area 51 that were already randomly configured, bottom time was limited to 20 minutes or less. Two types of hull-mounted depth recorders, a Furuno FCV-2000 dual

13 frequency depth sounder and a Sitex dual frequency depth sounder, were used to detect

the reef structures and to place an anchor as close as possible to a central location on a

corner. A dive team consisting of 2-3 people descended the anchor line to collect one

random sample from each of 6 cones closest to the anchor (regardless of cone

orientation). If all 6 scrapings were not obtained by the first dive team, a second team

was sent down at the same station to collect the remaining samples, noting not to sample

the same cones twice. From each selected cone, a 15 cm2 exterior quadrat (cone interiors were not sampled) was photographed using a 5.0 megapixel Casio Exilim with attached strobe arm, and scraped with a hammer and chisel into a zippered mesh collection bag until the bare cone surface was exposed. The mesh bags were numbered 1-6, and a photograph of each bag’s number was taken by divers prior to photographing the actual quadrat. This allowed the sample photographs to later be matched to the corresponding scraped material. A 15 cm ruler was held for scale in each photograph and used periodically during the scraping process to verify the size of the sample area.

The original sampling design called for one horizontal and one vertical sample from each selected cone (to give the best possible representation of organisms which might grow preferentially on different surface orientations); however, several attempts at collecting horizontal samples during the first collection trip to Area 53 revealed that there was not enough leverage to scrape from an overhead position. Also, without the assistance of gravity, scraped organisms floated in all directions and many were lost to

currents and foraging reef fish. The horizontal scrapings were incomplete every time,

resulting in three partial samples from Area 53’s northeast corner, and two samples with

no material from the northwest corner (for a total of N = 22 instead of the intended 24).

14 Methods were subsequently revised to include vertical scrapings only, and the two Area

53 stations with partial or missing samples were revisited in 2006 (material collected on

this trip was not analyzed in this study, see Statistical Analysis: Univariate Methods). All

scraped material was transferred on deck from the collection bags to corresponding

labeled jars, and fixed with a 10% buffered formalin-seawater solution. Depth and

temperature readings taken by dive computers were recorded. The same process was

repeated in May 2005 for Area 51.

In June 2005, four patches of the natural reef Julian’s Ledge (labeled A, B, C, and D)

were sampled similarly to the four corners of the artificial reefs. All four patches were

located at a single dive site, but were spaced out along a 40 m transect to simulate the

distance found between the artificial reef stations (Figure 2). Six 15 cm² quadrats were randomly selected at each station along the transect, and each was digitally photographed before scraping or chiseling all organisms from the rocky substrate.

Laboratory Processing of Scraped Samples

Once in the Southeastern Regional Taxonomic Center (SERTC) laboratory, samples were washed through a U.S. standard #35, 500 µm sieve to remove fine sediments, and transferred to a 70% EtOH solution. Processing began with a rough sort to remove chunks of cement (from the artificial reef samples), incidental vertebrates, and macroalgae, which were not included in any analysis. Total invertebrate biomass for each sample was then obtained by using a digital electronic balance to measure wet weights to the nearest gram. Barnacles were not included in biomass measurements due to the difficulty of distinguishing and separating them from the Julian’s Ledge samples,

15 which consisted of chunks of rock rubble with attached and unattached algae and epifauna (Figure 4). Therefore, in order to standardize biomass for the two reef types, all barnacles (including soft tissue, shells, and shell fragments) were identified and removed from each sample prior to weighing.

All remaining organisms were placed into one of two categories: “enumerated” or

“sessile.” Enumerated organisms included all mobile taxa, as well as several groups of sessile taxa where individuals could be easily counted, including anemones, sessile bivalves, and some serpulid polychaetes (the tubiculous serpulid Spirobranchus giganteus (Pallas 1766), which would usually be considered sessile, was counted because it was large enough to be easily distinguished and removed from the substrate. It should also be noted that the burrowing barnacle Kochlorine floridana Wells and Tomlinson,

1966, which lacks a shell and did not contribute significantly to biomass due to its small size and infrequent occurrence, was separated and included with the counted organisms.)

Sessile taxa included all encrusting and colonial organisms (Hydrozoa, Ectoprocta,

Octocorallia, Ascidacea, Porifera, as well as several species of sessile, tube-dwelling polychates including the tubiculous serpulids Filograna implexa Berkeley and

Chaetopteridae sp.).

All organisms were placed into broad taxonomic categories, identified to the lowest practical taxonomic level, and counted (or, for sessile species which were not counted due to the impossibility of separating them, marked as present or absent). For groups such as polychaetes and amphipods, which can break into multiple segments during sample processing, only animals with heads were counted to minimize confusion. When necessary, large organisms such as sponges and tunicates were dissected to remove

16 commensals, including polychaetes and amphipods. Tissue samples from sea cucumbers,

sponges, and octocorals were dissolved in bleach and the remaining structural elements

(ossicles, spicules, fibers, and sclerites) were examined using a compound microscope

(Figure 5, a-b).

Reference collections and taxonomic keys from the SERTC lab, Grice Marine Lab, and the Benthic Ecology labs from SCDNR and NOAA were utilized to assist with identifications, and the identifications of some specimens were confirmed by the SERTC staff. When necessary, specimens or photographs were sent to experts for identification.

Samples are currently stored at the Marine Resources Research Institute at the SCDNR, and voucher specimens will eventually be accessioned into the SERTC collection.

Analysis of Digital Photographs and Archived Video Data

Due to discrepancies in quality, digital photographs and videos were not consistently suitable for percent cover analysis, so observations made from these data were entirely qualitative and not statistically analyzed. Photographs were used to assist with the identification of organisms whose physical characteristics (i.e. shape, color) may have been altered during preservation. Archived videos of Area 53 and Area 51 collected by the SCDNR Artificial Reef Program, taken from deployment to the time of this study, were examined to determine duration from initial colonization to complete covering of the reef cones. Species that were present in photographs or videos but not collected in scrape samples were not included in statistical analysis.

17 Statistical Analyses: Univariate Methods

Not all of the data collected in this study were used in analyses. Meiofaunal

organisms (<500 µm) were excluded because they are considered to be part of the

infauna. The five samples collected from the northeast and northwest corners of Area 53

in 2006 were also excluded due to differences in species composition and abundance,

which may have been an artifact of their collection a year later than other samples in the

study. Lists of species from 2006 samples are provided in Appendix A. Species with

questionable identities (i.e. Undet. Phyla) or with more than one level of identification

were used only in total abundance calculations.

Biomass, number of individuals (n), number of species (s), and species richness (SR) were computed for quantitative data and used to compare reef sites. Species richness, which is similar to species number but is independent of sample size, was calculated using Margalef’s Expression (1958):

SR = (s-1)/ln N

Community indices for species diversity and species evenness were also used to compare reef sites. Diversity (H´) was calculated using the Shannon Index (Pielou 1966):

s

H´ = - Σ pi ln pi i = 1

where s is the total number of species and pi is the relative abundance of each species,

calculated as the proportion of individuals of a given species to the total number of

individuals in a community (or n i /N). The advantage of this index is that it takes into

account both the number of species and the relative evenness in the abundance of each

species. The index is increased either by having more unique species, or by having

18 greater species evenness (values range from 0 to 1). Evenness (J´) was calculated using

an expression from Pielou (1966):

J´= H´/ lnS

Community indices were calculated in Species Diversity and Richness 3.0 (Henderson

and Seaby 2002) using raw abundance data for all 70 samples.

The four stations under each treatment were nested within each main effect and were

analyzed per variable measured, allowing for both within-site and between-site

comparisons. However, mixed-model analyses of variance (ANOVAs) did not detect

significant within-site differences for any of the variables measured (Table 3), so the

nested study design was collapsed to create a larger sample size for each reef site.

Subsequently, results of this study focus on between-site differences only. Parametric

tests consisted of one-way ANOVAs in SPSS 15.0 (SPSS for Windows 2006) to compare the younger and older artificial reefs, and each artificial reef to the natural reef, for the means of the variables s and biomass. Bonferroni, Games-Howell and Student-

Newman-Keuls (SNK) multiple comparison tests were used to determine which means, if any, were significantly different from each other. Significance level for all tests was α =

0.05.

All univariate analyses incorporated tests to determine normality and homogeneity of variance, and when necessary, logarithmic [log10 (x+1)] transformations were applied

prior to the analyses of variance. Data for n, H´, J´, and SR failed to meet the

homogeneity of variance assumption of ANOVA even after log transformation was

applied, and were subsequently analyzed using the nonparametric Kruskal-Wallis test

(Sokal and Rohlf 1969), which compares medians among groups instead of means.

19 Mann-Whitney U-tests with Bonferroni adjustments were used as non-parametric post- hoc tests. Data were analyzed with and without outlying values (≥ +/- 2 standard deviations from the mean); however, the removal of outliers did not affect the outcome of statistical analysis, so only results from the original data set were presented in this study.

Following univariate analyses, components of variance analysis was performed on quantitative data using SPSS 15.0, to evaluate the overall sampling design of this study.

Statistical Analyses: Multivariate Methods

This step applied multivariate techniques to discriminate spatial variations between stations within a reef, as well as between reef types. In order to reduce the size of the large data set, hierarchical agglomerative cluster analysis (average linkage between- groups method) was performed on species abundance data from which rare species (those with fewer than 10 individuals) were eliminated, as well as infrequently occurring species

(present in fewer than 3 scrape samples). This reduced the number of species analyzed from 268 to 112. Similarity indices were calculated on composite samples, i.e. the cumulative abundance of all replicates at each station. The dissimilarity based on the

Canberra metric coefficient was then calculated between every pair of stations, and an abundance dissimilarity matrix was constructed. The Canberra metric coefficient was used because it is less sensitive to the high attribute scores, which characterized much of the data in this study, than the Bray-Curtis method of classification (Boesch 1977).

Furthermore, to reduce the large disparities in counts between species, log transformation

[log10 (x+1)] was applied to the original species abundance data before computing the

Canberra metric coefficients in Community Analysis Package (CAP) 1.52 (Henderson

20 and Seaby 1999). Normal (clustered by station) and inverse (clustered by species) classifications were produced for the data set, and a variable stopping rule (Boesch 1977) was applied to define species groups.

For similarity of stations based on presence/absence data, the entire species list was used, including enumerated organisms. In order to reduce the large size of the data set, infrequently occurring species (present in fewer than 3 collections) were removed, bringing the number of species analyzed to 247, and replicates for each station were pooled based on presence/absence. Jaccard similarity analysis was then performed using

CAP 1.52, which produced a matrix with Jaccard similarity coefficients ranging from 0 to

1. Both normal and inverse classifications were produced for the data set, and groups were defined using a variable stopping rule.

21

RESULTS

Description of Study Sites

Hydrological variables were not statistically compared among sites because of the

different seasons during which sampling occurred. Bottom temperatures at Area 53

ranged from 65°F to 69°F during April and May, while Area 51 and Julian’s Ledge were

sampled during July and August when temperatures were higher (74°F to 76°F; Table 1).

Video and diver observation showed that the Julian’s Ledge hard bottom site was characterized by rocky ledges and overhangs, which provided up to 2-4 feet of vertical relief. Invertebrate colonization ranged from dense to patchy, with some areas interspersed with bare rock and sand (Figure 6, a-d). In contrast, both Area 53 and Area

51 exhibited 100% biotic cover at the time of sampling (Figure 7, a-d; Figure 8, a-d).

Video data showed that both artificial reefs began to develop invertebrate communities

(beginning with barnacles) less than a month after deployment, and achieved full epifaunal cover by 6 months. Despite being structurally identical, the two artificial reefs appeared to be visibly distinct at the time of sampling, with Area 51 displaying more complexity due to the presence of large hydroids and sponges. Large organisms were frequently observed on the natural reef, along with several types of macroalgae, which were not observed on either of the artificial reefs. The presence of diverse fish

22 assemblages was also noted from videos, and by divers, at both the artificial and natural

reef sites.

Species Number, Species Richness, Abundance, and Biomass

A total of 384 species were found in the artificial and natural reef samples taken during spring/summer 2005 (complete species list in Appendix A). This included 24,940 counted individuals representing at least 268 invertebrate species, as well as 116 sessile species, which were marked as present or absent. 34% of all species collected were exclusive to the natural reef, 13% were exclusive to artificial reefs, and 53% were common to both reef types (i.e., common to Julian’s Ledge and at least one artificial reef; see appendices for lists). Julian’s Ledge shared more common species with Area 51

(137) than with Area 53 (115).

Total numbers of species collected at Julian’s Ledge, Area 51, and Area 53 were 303,

190, and 183, respectively (Figure 9b). Species numbers per 15 cm² quadrat ranged from

49 to 121 at Julian’s Ledge, 19 to 94 at Area 51, and 24 to 59 at Area 53. Mean species number per 15 cm² quadrat was significantly higher for Julian’s Ledge than for either of the artificial reefs, (Figure 9a; Table 3; one-way ANOVA, p < 0.05) and there was no significant difference between Area 53 and Area 51.

Results for species richness were similar to those for species number. Kruskal-Wallis detected a significantly higher median species richness at the Julian’s Ledge site than at either of the artificial reef sites, with the lowest median value for SR found at Area 53

(Figure 10; Table 3). There was no significant difference between Area 53 and Area 51.

23 Total abundances of all enumerated species for Julian’s Ledge, Area 51, and Area 53

were 5508, 14486, and 4946, respectively (Figure 11b). Abundance per 15 cm² quadrat

ranged from 64 to 527 at Julian’s Ledge, 19 to 3,080 at Area 51, and 47 to 476 at Area

53. Non-parametric statistical comparison detected a significant difference in median abundance between Area 51 and Julian’s Ledge, with Area 51 having a higher median abundance per quadrat (Figure 11a; Table 3; Kruskal-Wallis, p < 0.05). There was no significant difference between Area 53 and Julian’s Ledge, or between the two artificial reef sites.

Biomass values ranged from 48 to 768 g/15cm² for Julian’s Ledge, 64 to 801 g/15cm² for Area 51, and 93 to 346 g/15cm² for Area 53. Mean biomass did not differ significantly between the three reef sites (Figure 12; Table 3), although Area 51 had the highest value, and Julian’s Ledge had the lowest (Table 2).

Diversity Indices

All samples were analyzed for H´ and J´ (Table 3). Kruskal-Wallis tests revealed significantly higher median values (p < 0.05) at Julian’s Ledge for both H´ and J´ (Figure

13 (a-b)). The lowest median values of J´ and H´ were found at Area 53 (Table 2).

Species Composition – Artificial Reefs

Percentage contribution of major taxonomic groups to total abundance varied greatly between the younger and older artificial reef sites (Figures 14 and 15, respectively). Area

53 was numerically dominated (64%) by crustaceans (primarily amphipods, isopods, and decapods), while Area 51 was numerically dominated by polychaetes (62%). Molluscs

24 were the third most important group for both reef sites. The three most abundant species

at Area 53 were the amphipod Elasmopus sp., the isopod Carpias bermudensis H.

Richardson 1902, and the decapod Pseudomedaeus agassizii A. Milne-Edwards, 1880,

while the most abundant species at Area 51 were the polychaetes Syllis and Haplosyllis

sp. (also the most abundant species overall; Table 4), the amphipod Stenothoe sp., and tanaids in the family Leptocheliidae. Among the numerous crustaceans on Area 53, several specimens of an unusual pinnotherid crab (Figure 20, a-b) were found living in bivalves tentatively identified as Pododesmus rudis (Broderip, 1834). Taxonomic experts identified these specimens as Limnotheres nasutus, a species that has not previously been known to occur in this region or in this particular bivalve host. Interestingly, these crabs only occurred on Area 53’s northwest and southwest corners, although the host organism occurred on all three reef sites.

In terms of sessile taxa, sponges accounted for the greatest number of species at both artificial reefs, followed by hydroids, and bryozoans (Figures 17 and 18). Percentages of these taxa were relatively similar for both reefs. The barnacle Balanus trigonus Darwin,

1854 was the most frequently occurring species (100% of collections) at both artificial reef sites (Table 8) as well as overall (Table 7), although in many instances, clumps of barnacles were made up of both living and dead individuals, and dead shells were often

filled with mud or encrusting organisms. In addition to barnacles, Area 53 was

dominated (in frequency of occurrence) by the hydroid Sertularella conica Allman, 1877;

the bryozoans Bugula fulva Ryland, 1960 and Tricellaria sp.; and the encrusting

ascidians Trididemnum and Didemnum sp. Area 51 was dominated by the hydroids

Eudendrium carneum Clarke, 1882; Monostaechas quadridens McCrady, 1859; and

25 Sertularella conica; as well as the bryozoans Bugula fulva and Amathia vidovici Heller.

Other differences in community composition were also apparent, such as the presence of

the large sponges Dysidea fragilis (Montagu, 1818) and Ircinia sp. on Area 51 but not on

Area 53, and evidence (dead coral skeleton) of Oculina sp. on Area 51.

Species Composition – Natural Reef

Julian’s Ledge displayed a noticeably more even distribution of the abundances of

major taxa than either of the artificial sites (Figure 16). Polychaetes dominated

numerically (35%), closely followed by arthropods (21%) and molluscs (17%). The three

most abundant species were the polychaetes Syllis and Haplosyllis sp.; the ophiuroid

Ophiactis algicola H.L.Clarke, 1933; and the bivalve Timoclea grus (Holmes, 1858).

Other dominant organisms included the amphipod Elasmopus sp. and sipunculans (Table

6).

The barnacle Balanus trigonus was the most frequently occurring sessile species at all

Julian’s Ledge stations, occurring in 100% of collections (Table 9). Also dominant were

the bryozoan Crisulipora orientalis Canu and Bassler, 1928; the hydroid Thyroscyphus marginatus (Allman, 1877); and the sponge Clathrina sp., as well as the tubiferous polychaete Filograna implexa. Sponges accounted for the greatest number of sessile species at Julian’s Ledge, followed by bryozoans (Figure 19). Several species of

octocorals were found only in the Julian’s Ledge samples, although photographs of

material not collected from Area 51 (taken at the time of sampling) showed evidence of

Thesea sp.

26 Similarity Indices

The three reef sites were compared through the evaluation of their overall benthic

assemblages, as well as by major community components (in terms of abundance).

Normal Canberra metric cluster analysis performed on pooled abundance data for the 12

reef stations produced three distinct groups (Figure 21). Stations from each reef clustered together, indicating that the species composition among reefs was distinct. The station groups from Area 53 and Area 51 also clustered together, showing that the artificial reefs were more similar to each other than to Julian’s Ledge. Stations from Area 53 had the lowest within-site dissimilarity values, followed by Area 51. The Julian’s Ledge stations had the highest within-site dissimilarity values.

Inverse Canberra metric cluster analysis performed on 112 species produced 7 species groups (Figure 22; Table 10). The top cluster of groups (Groups A, B, and C) were those that were unique to a particular reef site. Group A was composed of species that

occurred primarily at the natural reef stations, with a few exceptions. One subgroup

contained 5 species that were also found on Area 51, and were characterized by low

abundance (17-25 individuals). Group B species occurred primarily at Area 51, with a

small subgroup that occurred both at Area 51 and Julian’s Ledge. Group C was

characterized by species that occurred primarily at Area 53. The bottom cluster of groups

contained species that occurred at all three reef sites (Groups D, E, F, and G); groups

were formed according to the sites at which their members were most or least abundant.

Group D was fairly ubiquitous, and included the most abundant and frequently occurring

species at all stations. This group also included a subgroup with species that did occur at

all three sites, but were extremely abundant at the artificial reef stations and rare at the

27 natural reef. Group E species occurred at all three reef sites, but were abundant at Area

51 and Julian’s Ledge, and rare at Area 53. This group included several species of bioeroders (members of the sipunculan order Aspidosiphoniformes and the mussels

Gregariella coralliophaga (Gmelin, 1791) and Lithophaga bisulcata d’Orbigny, 1842)), organisms that are characterized by their ability to bore into hard substrates. Group F species were found at all three sites, but occurred with greater frequency and abundance at the two artificial reef sites. Aside from a small subgroup, which was very abundant, this group was characterized by moderate to low abundance (11-69 individuals). Group

G was the smallest group, only containing 3 species. These species occurred at all three sites in low abundance (17-26 individuals).

Normal Jaccard similarity analysis for presence/absence of all species data yielded similar results to the normal Canberra metric cluster analysis (Figure 23). Stations clustered together based on which species were present or absent. Again, the highest similarity values for all three reef sites were between stations within each reef, showing that the faunal composition between reef sites was distinctly different. The two artificial reefs also appeared to have a higher level of similarity with each other than with the natural reef. However, similarity values between Julian’s Ledge and Area 51 stations were higher than those between Julian’s Ledge and Area 53 stations, suggesting that the species assemblages on Area 51 may have had more in common with the Julian’s Ledge stations than those of the younger artificial reef.

Although inverse Jaccard similarity analysis produced 12 species groups (Table 11;

Figure 24), the dendrogram produced by this analysis was not as satisfactory as the inverse Canberra metric dendrogram. The delineation of smaller groups was unclear due

28 to chaining, which occurs when each group is linked to the next by a slightly higher

vertical tie bar, suggesting that there are no suitable clusters in the dataset. There were obvious groups for each reef site (Groups B, I, and L) as well as a group of the most frequently occurring species at all sites (Group A). Group A was characterized by a high level of similarity because it was composed mostly of species which were found at all three reef sites, at the highest frequency of occurrence (8 to 12 stations). There was a small subgroup of species that were found only on the artificial reefs; these were

probably included with this group because of the high frequency of occurrence at these

sites. Group B was composed of species that occurred primarily at Area 51 (including

species that occurred at both A51 and Julian’s Ledge, or at all three sites, but with frequency of occurrence being highest at Area 51). All species in this group had a moderate to low frequency of occurrence (3 to 7 stations). Group C contained only two species, that occurred at all reef sites in moderate frequency (5 to 6 stations). These two species shared occurrence at common stations (Area 51, northwest; Area 53, northwest and southeast; Julian’s Ledge station B). Group D also contained only two species, that occurred in low to moderate frequency (3 to 6 stations), and shared occurrence at common stations (Area 53, southwest; Julian’s Ledge stations A and D). Groups E and F were characterized by a moderate similarity level, and were composed, with a few exceptions, of species that occurred at A51 and Julian’s Ledge in low to moderate frequency (2 to 6 stations). Species in Groups G and H were characterized by moderate similarity, and occurred primarily at A53 and Julian’s Ledge. There were a few exceptions that occurred at all three sites, but these were found with a higher frequency at

Julian’s Ledge, Area 53, or a combination of the two. Group I contained species with the

29 overall highest level of similarity, because the majority of them occurred only at Julian’s

Ledge, with a few exceptions that were found at both Julian’s Ledge and Area 51. These species were included with this group because they occurred at every Julian’s Ledge station, and only at one or a few Area 51 stations. There were also a few species that occurred at all 3 sites, but these also occurred at every Julian’s Ledge station and at only one or a few stations from the artificial reefs. Group J contained two subgroups, one with species that occurred at all three sites, and the other a mixture of species that occurred only at Area 51, species that occurred at both artificial reefs but primarily Area 51, and species that occurred at both Area 51 and Julian’s Ledge. However, all members of this group shared a low overall frequency of occurrence (2-3 stations). Group K was composed of a single species. Chrysopetalidae sp. A clustered out separately, probably because it was the only species with an evenly rare distribution at both Area 53 and

Julian’s Ledge (1 station each). Group L was entirely composed of species that occurred only at one or both artificial reef sites, with the majority found only or mostly at Area 53.

The only exceptions in this group were two species found at both Area 53 and one

Julian’s Ledge station (Pomatoceros sp. A and Eusynstyela floridana Van Name, 1921), and three species that were found at both artificial reef sites and one Julian’s Ledge station (Dendostrea frons (Linnaeus, 1758), Dulichiella sp., and Pilumnus sayi M. J.

Rathbun, 1897).

30

DISCUSSION

Community Composition

Epifaunal invertebrate assemblages collected from designed experimental artificial reef cones off the coast of Charleston were, for the most part, consistent with species found by previous studies to colonize artificial hard substrata in this region. Of the species that occurred in ≥25% of scrape samples collected from reefs formed by 5 sunken vessels (Wendt et al. 1989), approximately 68% were found in this study. Five out of 7 major species (approximately 71%) scraped from settlement plates deployed off the coast of Charleston by Van Dolah et al. (1988) were also found. Contrary to the results of these studies, however, neither hydroids nor bryozoans were found to be the most diverse sessile groups on Area 53 or Area 51. Instead, similar to the natural reef at Julian’s

Ledge, sponges comprised the greatest percentage of sessile species on both reefs.

Additionally, several types of large organisms, including sponges and octocorals, were

either photographed on or collected from Area 51. Although these organisms have been frequently observed on natural reefs in this region, they were completely absent from 1- year-old fouling plates and all ages (3.5 to 10 years) of sunken vessels in the previous studies, leading researchers to hypothesize that “1.) either reef communities were still undergoing succession, or that 2.) natural and artificial substrata differed in their capacity to attract or support populations of certain epifaunal invertebrates”. The diversity of

31 sponges on both artificial reefs in this study, the presence of large sponges and octocorals

on the 8-year-old reef, and the similarity of these patterns to the natural reef, may be an

indication that the type of reef material can have an effect on what organisms can

colonize; i.e. that concrete cones may provide more suitable habitat than scrap reefs for

slow-growing epifaunal organisms.

All invertebrate communities from Area 53 and Area 51 were characterized by a base

layer of the barnacle Balanus trigonus. B. trigonus is a common early colonizer, taking

advantage of its fast growth rate, short life span, and high fecundity to dominate new

fouling communities (Werner 1967). Some of the barnacles were dead, their shells

partially or fully overgrown with ascidians, hydroids, bryozoans, and encrusting sponges

(an indication that competition for space was occurring between early and later

colonizers), and barnacle biomass was greater on the younger artificial reef than on the

older one. This follows successional patterns observed on settlement plates by Van

Dolah et al. (1988) and Brown and Swearingen (1998), who observed that barnacles were initially dominant in new fouling communities, then decreased in percent cover over 12- month study periods as they were overgrown by colonial ascidians and hydroids.

Competition has been well-documented in marine benthic environments where space is limiting, although there has been conflicting evidence on whether solitary or colonial sessile organisms have a competitive advantage in the colonization of hard substrata

(Jackson 1977; Schoener 1982; Van Dolah et al. 1988).

Assemblages found on Julian’s Ledge natural reef were roughly similar to those collected from local hard-bottom habitats during previous invertebrate surveys (Wenner et al. 1983, 1984), although the higher species numbers and abundances reported from

32 these studies reflect sampling efforts that were beyond the scope of the current project.

Results of these surveys indicated that sponges and bryozoans were the most diverse

groups of sessile organisms on hard-bottom reefs in the South Atlantic Bight, and Julian’s

Ledge was no exception. Sponge communities were diverse, displaying not only

encrusting formations but also barrel and vase-shaped, branching, boring, spherical or

hemispherical, fan-shaped, and lobate masses.

One noticeable characteristic of Julian’s Ledge was the abundance of several types of macroalgae, including green, red, and a pink crustose coralline variety. Macroalgae was

not present in samples from either artificial reef, and was not observed in photographs or

videos from Area 53 and Area 51, although it has been observed growing on scrap reefs

and fouling plates in this region (Van Dolah et al. 1988; Wendt et al. 1989). Algae is an

important component of hard-bottom communities because of its role as a bioeroder,

habitat provider, and food source for benthic invertebrates and fish (Buckley and Hueckel

1985; Riggs et al. 1995). Depth (which affects light availability) was probably not

limiting to algal occurrence on artificial reefs in this case, as Area 51 is located in

shallower water than Julian’s Ledge and still did not support noticeable amounts of

macroalgae. Algal occurrence may have been inhibited by grazing pressure from fish,

which has been shown to be higher around artificial reefs than surrounding areas (Carter

et al. 1985; Einbinder et al. 2006). Area 51 and Area 53 are both inhabited by several

types of herbivorous reef fish, including angelfish, damselfish, and wrasses. Grazing on

algae may be even more prevalent on small artificial reef patches, which can accumulate

fish in greater densities than larger artificial or natural reefs (Jordan et al. 2005).

Additionally, Area 53 and Area 51 provide the protection of being relatively unfished.

33 Another possibility is predation on macroalgae by herbivorous amphipods and other

crustaceans, which can alter the structure of algal communities (Duffy and Hay 2000).

Both artificial reefs had a much higher concentration of amphipods than the natural reef,

including some herbivorous species (Deutella incerta (Mayer, 1903), Caprella penantis

Leach, 1814, etc.).

Surface orientation of hard substrata may also influence algal growth, although

studies have produced conflicting results on whether or not the effects are significant

(Knott et al. 2004; Chapman and Clynick 2006). Algae has been found on both vertical

and horizontal surfaces of artificial reefs worldwide, but it is a possibility that the lack of

horizontal samples taken from Area 53 and Area 51 excluded macroalgae, which may

grow preferentially on horizontal surfaces due to light availability (Glasby 1999; Connell

2000).

Community Indices

Invertebrate communities colonizing Julian’s Ledge displayed greater H´ and J´

values than either artificial reef, in agreement with previous artificial/natural reef comparisons that have found natural communities to be more diverse and less variable

than artificial ones (Badlamenti et al. 2002; Perkol-Finkel and Benayahu 2005; Thanner

et al. 2006). These results were expected, due to the presence of large suspension-

feeding organisms that can facilitate increases in biodiversity by providing habitat

heterogeneity (Nicoletti et al. 2007). Hard-bottom reefs exhibit a complexity of bottom

types such as crevices and sand patches, allowing for the coexistence of species that

“prefer” different habitats (Wenner et al. 1983). For example, the tube-building serpulid

34 polychates Spirobranchus giganteus and Filograna implexa were found only on the natural reef. S. giganteus is a gregarious species and an obligate coral associate, with larvae that settle preferentially near conspecifics and on live hermatypic corals in tropical

and subtropical regions, where they are overgrown and held in place by coral skeletons

(Hunte et al. 1990). The steep, smooth surfaces provided by reef cones are probably

unable to support the weight of the large, heavy calcareous tubes secreted by these

worms. Filograna implexa, also a gregarious species, colonizes rocky crevices and may

prefer the complexity of natural limestone reefs to artificial habitat. Several species of

brittle stars (including Ophiactis algicola and Ophiactis savignyi Müller and Troschel,

1842 ) were also highly abundant in samples from Julian’s Ledge (accounting for 15% of

total abundance), but were relatively rare in artificial reef samples (accounting for only

1% of total abundance at Area 53, and < 1% at Area 51). Brittle stars are cryptic animals that prefer the protection and low-light conditions of complex habitats such as coral rubble, clumps of coralline algae, and sponges (Hendler et al. 1995).

Julian’s Ledge displayed the significantly highest mean species number and highest median species richness, but highest total and median abundance of individuals was observed at Area 51. This pattern of a few species in high abundance has been observed on other artificial reefs (Connell 2001; Badalamenti et al. 2002). In this study, high abundance values at Area 51 were linked to the polychaetes Syllis and Haplosyllis sp.

(Figure 25a). Although these polychaetes occurred at all reef sites and were second only to Balanus trigonus in overall frequency of occurrence, their distribution was most noteworthy at Area 51. Due to unusually large numbers of these worms in several samples from the northeast, northwest, and southeast stations, abundance values appeared

35 much higher than those of the natural reef. The high abundances seemed to be correlated

with the presence of dense sponge mats, including Lissodendoryx sp., which occurred in all 6 samples where abundance of Syllis and Haplosyllis sp. was greatest (Figure 25b).

Sponges often act as microcosms, accumulating large numbers of symbiotic and parasitic

species, including polychates in the family Syllidae (Lopez et al. 2001). At least 36

known host sponges have been identified for syllid polychaetes, and although

Lissodendoryx is not among them, the samples containing this sponge were filled with

syllids, most of which were removed directly from sponge tissue.

Interestingly, if percent contribution to total abundance by major taxa were to be

recalculated for Area 51 with Syllis and Haplosyllis sp. removed, arthropods (specifically,

amphipods, decapods, and isopods) would make up approximately 63% of enumerated

organisms, much like Area 53. Julian’s Ledge would also be numerically dominated by

arthropods without the presence of Syllis and Haplosyllis sp. This emphasizes the

importance of polychaetes, and the organisms they inhabit, in the structuring of

invertebrate communities on both Julian’s Ledge and the 8-year-old artificial reef in this

study.

Age of Artificial Reefs

In this study, substrate type probably played an important role in determining the

structure of invertebrate communities. All of the multivariate analyses indicated that the

8 artificial reef stations, regardless of age, had higher similarity to one another than to

any of the natural reef stations. Julian’s Ledge was more diverse, and was distinct from

both artificial reefs due to the large number of unique taxa that occurred there and

36 nowhere else. One possible explanation for this may be the different structural features

that Area 53 and Area 51 offered in comparison to the natural reef. When artificial and

natural reefs offer similar surface orientations, distances from the seabed, and

complexity, their epifaunal communities can converge over time; otherwise, their

communities will remain distinct regardless of age (Carr and Hixon 1997; Perkol-Finkel and Benayahu 2006, 2007). This can be due to variations in habitat preference, predation, current, and sediment load. For example, according to Baynes and Szmant

(1989), sediments can be detrimental to sessile benthic organisms because they “clog the pores of ascidians and sponges, inhibit polyp feeding, …inhibit the exchange of dissolved nutrients and gases, …inhibit planular settlement and development, and physically abrade and bury encrusting organisms”. For these reasons, it has been suggested that artificial reefs should maximize the amount of vertical surfaces in order to maximize epifaunal growth. Area 53 and Area 51 offered a mixture of vertical and horizontal surfaces

(although the majority sampled were vertical). In contrast, Julian’s Ledge did not offer vertical surfaces, and some of the scraped quadrats were located only a few centimeters above the sea floor. Many of these horizontal surfaces were covered by sand patches, possibly inhibiting the growth of organisms that may be susceptible to sedimentation and sand scour. This, together with the larger overall surface area of the habitat, may have caused the Julian’s Ledge samples to have less overall percent cover than the artificial reefs. The lower biomass observed at natural reef stations was probably also correlated with surface orientation and patches of uncolonized space. Biomass results for Area 53 and Area 51 agreed with Wendt et al. (1989), who did not notice a significant age trend in biomass for 5 sunken vessel artificial reefs. However, the biomass of Area 51 was

37 slightly higher than that of Area 53, due to the presence of a few large organisms and

thick epifaunal growth.

Despite inherent differences between the artificial and natural reefs in this study,

evidence did exist that some degree of convergence is possible over time. Sponges were by far the most diverse group of sessile taxa at both the natural and artificial sites. Also,

consistent with the findings of Wendt et al. (1989), there was a large group of species

common to all three sites. According to these authors, this would suggest that the

development of a stable community might be achieved on designed reefs in as little as

two years.

Results of the Jaccard analyses also indicated that Julian’s Ledge exhibited a slightly

higher level of similarity to Area 51 than to its younger counterpart, due to the numerous

groups and subgroups of species which were found at both sites but not on Area 53. Age

has been shown to be an important factor in faunal similarity when the same artificial reef

was sampled over a 20-year period, with species number increasing over time (Nicoletti et al. 2007). A slight upward trend in all measured variables did exist between Area 53

and Area 51, which may have been correlated with increasing age of the artificial reefs.

Other characteristics of Area 51 suggest that its invertebrate communities shared more

similarities with the natural site, including the larger number of common species, the

presence of large sponges and octocorals, and the dominance of polychaetes as opposed

to crustaceans. Gravina et al. (1989) studied colonization of an artificial reef by

polychaetes and found that numbers of species and individuals increased with reef age as

biogenic structures such as barnacle shells accumulated suspended particles (sediment,

pseudofeces). This increased heterogeneity of the habitat, enabling soft-bottom species

38 to colonize. Polychaetes were found inhabiting both large epifaunal organisms and small sediment deposits on Area 51 in the present study, demonstrating that to some degree, an

older designed reef can offer a mixture of microhabitats similar to those of a natural hard-

bottom reef.

Influence of Other Factors

Aside from reef age and type, several environmental factors may have contributed to

the observed differences between Area 53, Area 51, and Julian’s Ledge. It is well-known

that season of deployment can lead to multiple stable end points in fouling communities,

because many organisms have seasonal patterns of larval dispersal (Sutherland 1974; review by Svane and Petersen 2001). Similarly, sampling during different seasons can lead to shifts in the abundance of certain taxa. While these changes are most apparent between warmer (spring/summer) and cooler (fall/winter) seasons, the sampling of Area

53 in April and May, Area 51 in July, and Julian’s Ledge in August may have had an affect on the species composition of their invertebrate communities (Brown and

Swearingen 1998).

Location of the reef sites may have affected the numbers and types of organisms found in this study. Marine benthic communities are not closed ecosystems, so materials are often exchanged between individual islands or “patches” (Levin and Paine 1974).

Area 51 was located slightly closer to the natural site, which could have affected the availability of local larval recruits and contributed to its higher species numbers, abundance, and diversity (Van Dolah et al. 1988). Differences in depth can also be associated with patterns of community composition (Rule and Smith 2007) and changes

39 in diversity due to altered light conditions (Glasby 1999). Distributions of some sessile

species have been found to be affected by depth differences as small as 4 m, with the

shallower depths displaying greater s, biomass, and H´ (Moura et al. 2007). The absence

of large sponges on Area 53, however, should probably not be attributed to depth, as the

range of some of the sponges found on Area 51 (Ircinia, specifically) extends to 30m

(Maldonado and Young 1998).

The same holds true for Eudendrium carneum, a large, tree-like hydroid, which was not found on Area 53, but visually characterized Area 51, in some cases providing vertical relief over 25 cm. Video data showed small E. carneum colonies on Area 51 just over a year after deployment, and previous studies have reported finding E. carneum at

depths of 59-67 m (Wenner et al. 1984), eliminating depth and age of reefs as factors in

the distribution of this particular species. Larval recruitment patterns of benthic

organisms normally vary in both space and time, so any number of conditions (currents,

larval settlement cues, predation, competition, historical disturbance events, etc.) could

be responsible for the differential success of certain species on reefs deployed in different

locations, several years apart from one another (Sutherland 1974; Sutherland and Karlson

1977; review by Svane and Petersen 2001).

Implications for Fisheries Management

Area 53 and Area 51, despite differences with Julian’s Ledge, did provide habitat

structure that eventually attracted fishes, suggesting the achievement of some functional

similarities with natural reefs. Based on video data of newly deployed reef cones, which

showed primarily small fish and juveniles, and on videos and diver observations of more

40 mature cones, the appearance of larger fish species including black sea bass, gray

triggerfish, gag and scamp grouper, and snapper, may have been correlated with the

development of epifaunal assemblages on these reefs. A study conducted by Hueckel and

Buckley (1987) in Puget Sound, Washington, examined 11 artificial reefs ranging from

newly deployed to 49 years old, to determine the relative importance of reef-produced

prey organisms in the diets of reef fish. On new, barren artificial reefs, early-colonizing

fish species primarily used the sand habitat surrounding the reef structures as a source of

food. The later appearance of reef-foraging fish species was associated with the

development of sessile epibenthic invertebrates on the reefs, suggesting that increased

availability of epifaunal prey items created habitat for fish species that were previously

unable to colonize. On the oldest reef, 70% of fish were supported by reef-associated

prey. Many of the commercially important fish species that inhabit South Carolina’s

artificial reefs, including black sea bass, gray triggerfish, sheepshead, and porgy, obtain

portions of their diets from reef-dwelling organisms such as barnacles, tunicates, shrimp,

bivalves, and crabs (Lindquist et al. 1985; Sedberry 1987, 1988; Lindquist et al. 1994;

Pike and Lindquist 1994; Vose and Nelson 1994). Black sea bass, for example, have

been found to “feed heavily on invertebrate species that are closely associated with reef

habitats,” including both mobile and sessile invertebrates (Sedberry 1987). The added

habitat complexity and food sources provided by the development of epifaunal assemblages may have been a contributing factor in attracting fish to Area 53 and Area

51; if so, observed similarities in the invertebrate communities of artificial and natural sites in this study could have obvious fisheries management implications for designed artificial reefs.

41

Future Directions

The scraped material collected from Area 53 in 2006 contained 17 taxa that had not been collected during the previous year, and octocoral colonies were present in the 2006 digital photographs from Area 53’s northeast and northwest corners. This was also apparent in the presence in this study of so many “rare” species on Julian’s Ledge, along with the absence of some species that are known to occur in both natural and artificial habitat types (i.e. octocorals on Area 53 and Area 51; Arbacia punctulata (Lamarck,

1816) from preliminary site photographs of Area 53 and Area 51).

It is possible that either 1.) successional changes in invertebrate community structure were continuing to take place from 2005 to 2006, or 2.) that increasing sampling efforts would have yielded greater species numbers and perhaps more reliable estimates of diversity and community composition. Components of variance analysis showed that most of the variance in this study was due to random error (approximately 76-90%) for each measured variable, with the exception of s and SR. For these variables, variability among reef stations contributed approximately 50% to the total variance (Table 12).

Based on this, one suggestion would be to increase sampling effort associated with any future studies for both artificial and natural sites. Since some studies have found that new artificial reefs take 10-15 years to mimic natural reefs (Aseltine-Neilson et al. 1999), adding a temporal aspect to sampling could help determine whether similarity becomes even higher between these artificial and natural reefs after additional time has passed.

This should be timed to include an examination of seasonal changes in community structure. Additional sampling would also serve to isolate any effects seen in the present

42 study that could be attributed to depth, proximity to existing hard bottom habitat, surface orientation, or the natural temporal and spatial variability of fouling communities. If the reef types remain distinct indefinitely, then similarities or differences in community composition between reef types can most likely be attributed to physical and environmental variables, rather than reef age.

Furthermore, the conclusions drawn from this study are limited by the fact that only one set of artificial and natural reefs were sampled. Thus, without examining other reef systems, it is difficult to determine how similar Area 53 and Area 51 would be when compared in general to other hard bottom areas in the South Atlantic Bight.

43

CONCLUSIONS

The results of this study showed that invertebrate communities found on two of South

Carolina’s designed artificial reefs and a nearby natural reef were distinct even after a period of 8 years. Based on the cluster analyses and on the presence/absence of some organisms at both artificial sites versus the natural site, this was probably due largely to differences in structural features between the two habitat types. It is recommended here that for rehabilitation purposes, reefs should be designed with a complex series of shelves, scarps and ledges more characteristic of natural habitats, in order to produce invertebrate communities that are as close as possible to those that exist on natural reefs in the South Atlantic Bight. However, notable similarities did exist between the artificial reefs and Julian’s Ledge, and these similarities appeared to increase with reef age, becoming more evident in the characteristics of the older artificial reef.

The information collected in this study serves as the SCDNR Artificial Reef

Program’s first catalogue of invertebrate species for any of their existing experimental designed artificial reefs, and baseline data for any future ecosystem research associated with Area 53 or Area 51. Overall, designed experimental reef structures were successful in the provision of habitat for rich and diverse epibenthic assemblages, as well as a wide variety of commercially important fish species, with indications that they may be more effective than secondary-use materials in their potential for mimicking natural hard-

44 bottom habitat. Even if reef cones are too structurally different from natural reefs to ever produce indistinguishable invertebrate communities, local diversity will be increased by

the presence of organisms that would not have ordinarily been able to colonize the area.

45

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Vose, F.E., Nelson, W.G. 1994. Gray triggerfish (Balistes capriscus Gmelin) feeding from artificial and natural substrate in shallow Atlantic waters of Florida. Bulletin of Marine Science. 55(2-3): 1316-1323.

Wahl, M. 1989. Marine Epibioses I. Fouling and antifouling: some basic aspects. Marine Ecology Progress Series. 58: 175-189.

Wendt, P.H., Knott, D.M., Van Dolah, R.F. 1989. Community structure of the sessile biota on five artificial reefs of different ages. Bulletin of Marine Science. 44(3): 1106-1122.

Wenner, E.L., Knott, D.M., Van Dolah, R.F., Burrell, Jr., V.G. 1983. Invertebrate communities associated with hard bottom habitats in the South Atlantic Bight. Estuarine, Coastal and Shelf Science. 17: 143-158.

------, Hinde, P., Knott, D.M., Van Dolah, R.F. 1984. A temporal and spatial study of invertebrate communities associated with hard-bottom habitats in the South Atlantic Bight. NOAA Technical Report. NMFS 18. 104pp.

Werner, W.E. 1967. The distribution and ecology of the barnacle, Balanus trigonus. Bulletin of Marine Science. 17: 64-84.

54

FIGURES

55

Figure 1. Study locations, showing approximate position of artificial reefs (Area 51 and Area 53) and the natural hard bottom area (Julian’s Ledge) to the Charleston peninsula. Reef dimensions are not to scale, and due to the confidential nature of Area 51 and Area 53 coordinates, reef positions are not exact. Map courtesy of Jessica Boynton, SCDNR/MRD.

56

NE D

10 mi C

NW B Area 53 Julian’s Ledge SE A Natural Reef

SW 5 mi NE

13 mi

NW Area 51 SE

SW

Figure 2. Configuration of artificial and natural reefs. The four sampling stations at Area 53 and Area 51 are indicated by NE (northeast), NW (northwest), SE (southeast), and SW (southwest). The four sampling stations at Julian’s Ledge are indicated by A, B, C, and D. Figure is not to scale.

57

0.7 m top diameter

0.91 m height 20 cm

1.22 m base diameter

Figure 3. Dimensions of the Swiss Cone, the concrete reef units that comprise Area 53 and Area 51. Image courtesy of the SCDNR Artificial Reef Program.

58

Figure 4. Photograph of a preserved scrape sample collected from Julian’s Ledge natural reef during August 2005.

59

a.)

b.)

Figure 5 (a-b). Digital photographs of ossicles, viewed with a compound microscope, and corresponding sea cucumber specimens. a.) Left: ossicle from Istichopus badionotus. Right: corresponding juvenile specimen of I. badionotus from Julian’s Ledge. b.) Left: ossicles from Ocnus pygmaeus. Right: corresponding juvenile specimen of O. pygmaeus from Julian’s Ledge.

60

a.) b.)

c.) d.)

Figure 6 (a-d). Selected digital photographs of scrape samples collected from Julian’s Ledge during 2005. a.) Station A, sample V-0004; b.) station B, sample V-0003; c.) station C, sample V-0002; and d.) station D, sample V-0004.

61

a.) b.)

c.) d.)

Figure 7 (a-d). Selected digital photographs of scrape samples collected from Area 53 during 2005. a.) Northeast station, sample V-0001; b.) northwest station, sample V-0003; c.) southeast station, sample V-0002; d.) southwest station, sample V-0006.

62

a.) b.)

c.) d.)

Figure 8 (a-d). Selected digital photographs of scrape samples collected from Area 51 during 2005. a.) Northeast station, sample V-0006; b.) northwest station, sample V-0003; c.) southeast station, sample V-0005; d.) southwest station, sample V-0002.

63 a.)

90

80 *

70

60

50

40 74.63

30 57.54 48.77 20

Mean No. Species10 (per 15 cm²)

0 A53 A51 JL N = 22 N = 24 N = 24 b.)

350

Enumerated 300 Presence/ Absence

250

200 224

150

143 142 100 Total Number of Species Number Total

50 79 40 48 0 A53 A51 JL N = 22 N = 24 N = 24

Figure 9 (a-b). a.) Mean number of species (s) per 15 cm² quadrat for each reef site, and b.) total number of species in all quadrats for each reef site. Error bars represent one standard error from the mean. Asterisks (*) indicate a significant difference between sites at a 0.05 level of significance. N indicates sample size.

64

12 * 10

8

6

9.87 4 7.91 6.99

2 Median Margalef Index (per 15 cm²) (per Index Margalef Median 0 A53 A51 JL N = 22 N = 24 N = 24

Figure 10. Mean species richness (SR) per 15 cm² for Area 53, Area 51, and Julian’s Ledge. Error bars represent one standard error from the mean. N indicates sample size.

65 a.) 500

450 * 400

350

300

250

200 348.0 150

228.5 100 216.5

Median Abundance (per 15 cm²) 50

0 A53 A51 JL N = 22 N = 24 N = 24 b.)

16000

14000

12000 e

10000

8000 14486 6000 Total Abundanc 4000

4946 5508 2000

0 A53 A51 JL N = 22 N = 24 N = 24

Figure 11 (a-b). a.) Median number of individuals (n) per 15 cm² quadrat for each reef site, and b.) total number of individuals in all quadrats for each reef site. Error bars represent one standard error from the mean. Asterisks (*) indicate a significant difference between sites at a 0.05 level of significance. N indicates sample size.

66

300

250

200

150

236.29 100 199.23 182.13

50 Mean Biomass (per 15 cm²)

0 A53 A51 JL N = 22 N = 24 N = 24

Figure 12. Mean biomass per 15 cm² scrape sample for Area 53, Area 51, and Julian’s Ledge. Error bars represent one standard error from the mean. N indicates sample size.

67 a.)

3.6 * 3.5

3.4

3.3

3.2

3.1 3.43 3 Shannon Index (per 15 cm²)

n 2.9 2.98 3.02 2.8 Media

2.7 A53 A51 JL N = 22 N = 24 N = 24 b.)

0.58 * 0.56

0.54

0.52

0.55 0.5 0.54

0.51 0.48 Median Pielou Index (per 15 cm²)

0.46 A53 A51 JL N = 22 N = 24 N = 24

Figure 13 (a-b). Median values of a.) species diversity (H´) and b.) species evenness (J´) per 15 cm² for Area 53, Area 51, and Julian’s Ledge. Error bars represent one standard error from the mean. Asterisks (*) indicate a significant difference between sites at a 0.05 level of significance. N indicates sample size.

68

1% 1% 2% 2%

9% Polychaeta Mollusca Cnidaria 38% Sipuncula Arthropoda 64% Echinodermata 15% Platyhelminthes Polychaeta Amphipoda 12% Decapoda 20% Isopoda

Figure 14. Percent contribution of major enumerated taxa (≥1%) to the total abundance of Area 53. Arthropoda is expanded to show the percentage contribution of its major orders (≥1%) to total abundance.

69

5% 2% 2%

Polychaeta Mollusca Cnidaria 18% Sipuncula Arthropoda 29% Amphipoda Polychaeta 5% Decapoda Isopoda 62% 2% Pycnogonida 1% Tanaidacea 3%

Figure 15. Percent contribution of major enumerated taxa (≥1%) to the total abundance of Area 51. Arthropoda is expanded to show the percentage contribution of its major orders (≥1%) to total abundance.

70

15% 8% 1% 3%

Polychaeta Mollusca 17% Cnidaria 12% Sipuncula Echinodermata Arthropoda 21% Nemertea 7% Amphipoda 1% Decapoda Isopoda Polychaeta 1% Phyllocarida

35%

Figure 16. Percent contribution of major enumerated taxa (≥1%) to the total abundance of Julian’s Ledge. Arthropoda is expanded to show the percentage contribution of its major orders (≥1%) to total abundance.

71

5% 28%

Ascidiacea 18% Calcarea Demospongiae Porifera 33% Ectoprocta 15% Hydrozoa Maxillopoda

20%

15%

Figure 17. Percent contribution of major sessile taxa to the total number of sessile species from Area 53. Porifera is expanded to show the percentage contribution of its major classes to total number of sessile species.

72

4% 26%

Ascidiacea 13% Calcarea Porifera Demospongiae 32% Ectoprocta 21% Hydrozoa Maxillopoda

25%

11%

Figure 18. Percent contribution of major sessile taxa to the total number of sessile species from Area 51. Porifera is expanded to show the percentage contribution of its major classes to total number of sessile species.

73

3% 4% 3% 6%

Ascidiacea 8% Calcarea Demospongiae Porifera 42% Ectoprocta 35% Hydrozoa Maxillopoda 33% Anthozoa Tubiferous Polychaeta

8%

Figure 19. Percent contribution of major sessile taxa to the total number of sessile species from Julian’s Ledge. Porifera is expanded to show the percentage contribution of its major classes to total number of sessile species.

74

a.)

b.)

Figure 20 (a-b). Dorsal views of a.) female and b.) male specimens of Limnotheres nasutus, collected from the northeast and northwest stations of Area 53. Scale bars are in millimeters.

75

DISSIMILARITY

A51

A53

JL

Figure 21. Normal Canberra Metric cluster dendrogram showing 3 station groups (indicated by brackets on right). Replicates for each station were pooled by the sum of species abundance. Rare species (less than 10 individuals or occurring in fewer than 3 collections) are excluded.

76 DISSIMILARITY

A

B

C

D

E

F

G

Figure 22. Inverse Canberra Metric cluster dendrogram showing 7 species groups (indicated by brackets on right). Replicates for each station were pooled by the sum of species abundance. Rare (less than 10 individuals) or infrequently occurring (present in fewer than 3 collections) were excluded.

77

SIMILARITY

0 1

JL

A51

A53

Table 23. Normal Jaccard similarity dendrogram showing 3 station groups. Replicates for each station were pooled by presence or absence of species at each station. Infrequently occurring species (present in fewer than 3 collections) were excluded.

78

SIMILARITY

0 1

A

B C D E F G

H

I

J K L

Figure 24. Inverse Jaccard similarity dendrogram showing 12 species groups. Replicates for each station were pooled by presence/absence. Infrequently occurring species (present in fewer than 3 collections) were excluded.

79 a.) 4 A51 w/ polychaetes 3.5 A51 w/o polychaetes

3 ´) 2.5 H

2

1.5 Diversity (

1

0.5

0

3 14 16 24 32 38 47 61 99 29 40 2 6 1500 Abundance of Syllis and Haplosyllis sp. b.)

3500 w/ Lissodendoryx sp. .

sp 3000 w/o Lissodendoryx sp.

2500

Haplosyllis 2000 and 1500

Syllis 1000

500

0 Abundance of 1 5 5 5 3 -0 -0 0 -03 -0 -01 -0 E E W-01 W- N NE-03 N N NW-03 N SE-01 SE SE SW SW SW-05 Area 51 Collection

Figure 25 (a-b). a.) Correlation between abundance of Syllis and Haplosyllis sp. and diversity (H’) in samples collected from Area 51 in 2005, and b.) abundance of Syllis and Haplosyllis sp. in Area 51 collections, noting presence/absence of the sponge Lissodendoryx sp.

80

TABLES

81

Table 1. Collection dates and measurements of depth and water temperature for artificial reef (A53 and A51) and Julian’s Ledge natural reef (JL) stations visited in 2005 and 2006. Duplicate sampling trips (those conducted in 2006) are indicated with asterisks (*).

Station Date Visited Depth (m) Temp (°F) A53-NE 4/21/2005 32 65 A53-NW 4/21/2005 31 65 A53-SE 5/10/2005 32 69 A53-SW 5/10/2005 30 69 A53-NE* 5/10/2006 32 65 A53-NW* 5/10/2006 31 67 A51-NE 7/13/2005 21 75 A51-NW 7/13/2005 21 75 A51-SE 7/13/2005 22 76 A51-SW 7/13/2005 21 75 JL-A 8/10/2005 27 75 JL-B 8/10/2005 27 74 JL-C 8/10/2005 26 75 JL-D 8/10/2005 27 75

82

Table 2. Community structure values per 15 cm² [number of individuals (n), number of species (s), species richness (SR), biomass, species diversity (H´), and species evenness (J´)] for stations sampled at the younger artificial reef (Area 53), older artificial reef (Area 51), and Julian’s Ledge in 2005. Variables with median values shown are indicated with an asterisk (*); all other values are means.

n* s SR* biomass H´* J´* Area 53 - Overall 228.5 48.77 6.983 199.23 2.983 0.512

Station NE 117.5 43.00 6.226 200.67 2.992 0.535 NW 247.0 51.75 7.177 206.75 3.090 0.553 SE 215.0 48.50 6.420 139.50 3.066 0.548 SW 344.0 52.83 7.208 252.50 2.936 0.525 Area 51 - Overall 348.0 57.54 7.912 236.29 3.016 0.536

Station NE 541.5 49.33 6.438 164.17 2.089 0.374 NW 324.0 50.00 6.966 211.67 2.736 0.489 SE 221.5 55.83 8.261 210.83 3.300 0.590 SW 569.0 75.00 8.337 358.50 3.057 0.547 Julian’s Ledge - Overall 216.5 74.63 9.870 182.13 3.429 0.545

Station A 373.0 93.33 11.600 159.17 3.575 0.639 B 178.5 66.17 8.719 77.17 3.193 0.571 C 194.0 71.50 10.725 249.00 3.586 0.641 D 63.5 67.50 9.651 243.17 3.345 0.598

83

Table 3. Summary of statistical analyses of community structure values [number of individuals (n), number of species (s), species richness (SR), biomass, species diversity (H´), and species evenness (J´)], showing both significant (S) and non-significant (NS) differences between and within reef sites, and associated p-values. Determination of significance is based on p< 0.05. Tests where data were log-transformed are indicated by (*). Kruskal-Wallis tests are indicated by (**). Artificial reef stations are labeled NE (northeast), NW (northwest), SE (southeast), SW (southwest), and Julian’s Ledge stations are labeled A, B, C, and D.

Variable n s SR biomass H' J' Between Reefs S S S NS S S p-value 0.016** 0.000 0.000** 0.167* 0.000** 0.000** A51>JL, JL>A53, JL>A53, JL>A53, JL>A53, 0.024 0.000 0.000 0.000 0.000 JL>A51, JL>A51, JL>A51, JL>A51, 0.001 0.000 0.000 0.000

Within Reef (Between Stations) NS NS NS NS NS NS p-value 0.640* 0.160* 0.150* 0.403 0.067* 0.055*

84

Table 4. Ranking of most abundant species overall (> 1%), showing total abundance, percent of total abundance, and a summary of abundance of each species by reef site.

Total Of % Total Area Area Julian’s Scientific Name Abundance Abundance 53 51 Ledge Syllis and Haplosyllis sp. 8847 35.47 91 7949 807 Stenothoe sp. 1054 4.23 225 822 7 Elasmopus sp. 1033 4.14 585 215 233 Carpias bermudensis 854 3.42 575 268 11 Chama congregata 610 2.45 121 366 123 Pseudomedaeus agassizii 563 2.26 343 214 6 Ericthonius brasiliensis 545 2.19 240 286 19 Undet. Terebellidae 545 2.19 174 185 186 Leucothoe spinicarpa 497 1.99 126 355 16 Undet. Sipuncula 472 1.89 77 184 211 Ophiactis algicola 438 1.76 8 13 417 Gammaropsis sp. 434 1.74 230 55 149 Undet. Leptocheliidae 400 1.60 0 393 7 Undet. Actiniaria 353 1.42 81 242 30 Polydora sp. 318 1.28 105 194 19 Cymadusa sp. 306 1.23 151 105 50 Hiatella arctica 292 1.17 157 62 73 Timoclea grus 284 1.14 13 37 234 Undet. Aspidosiphoniformes 279 1.12 2 44 233 Lumbrineris inflata 271 1.09 61 76 134 Microjassa tetradonta 251 1.01 14 237 0 Micropanope sp. 236 0.95 186 49 1 Caprella penantis 225 0.90 1 221 3 Deutella incerta 206 0.83 175 28 3 Undet. Nemertea 202 0.81 2 51 149 Photis sp. 186 0.75 27 159 0 Synalpheus townsendi 183 0.73 32 96 55 Undet. Cirratulidae 183 0.73 11 147 25 Hesionidae sp. A 179 0.72 51 94 34 Ophiactis savignyi 173 0.69 0 0 173 Spio sp. 172 0.69 99 49 24 Eunice antennata 169 0.68 112 37 20 Megalobrachium soriatum 166 0.67 17 74 75 Proceraea sp. 162 0.65 104 48 10 Websterinereis tridentata 144 0.58 94 27 23 Undet. Sabellidae 136 0.55 9 40 87

85

Table 5. Rank by abundance of the top 25 most abundant species in samples collected from Area 53 and Area 51 in 2005.

% of % of Area 53 Abundance Total Area 51 Abundance Total Elasmopus sp. 585 11.83 Syllis and Haplosyllis sp. 7949 54.87 Carpias bermudensis 575 11.63 Stenothoe sp. 822 5.67 Pseudomedaeus agassizii 343 6.93 Undet. Leptocheliidae 393 2.71 Ericthonius brasiliensis 240 4.85 Chama congregata 366 2.53 Gammaropsis sp. 230 4.65 Leucothoe spinicarpa 355 2.45 Stenothoe sp. 225 4.55 Ericthonius brasiliensis 286 1.97 Micropanope sp. 186 3.76 Carpias bermudensis 268 1.85 Deutella incerta 175 3.54 Undet. Actiniaria 242 1.67 Undet. Terebellidae 174 3.52 Microjassa tetradonta 237 1.64 Hiatella arctica 157 3.17 Caprella penantis 221 1.53 Cymadusa sp. 151 3.05 Elasmopus sp. 215 1.48 Leucothoe spinicarpa 126 2.55 Pseudomedaeus agassizii 214 1.48 Chama congregata 121 2.45 Polydora sp. 194 1.34 Eunice antennata 112 2.26 Undet. Terebellidae 185 1.28 Polydora sp. 105 2.12 Undet. Sipuncula 184 1.27 Proceraea sp. 104 2.10 Photis sp. 159 1.10 Spio sp. 99 2.00 Undet. Cirratulidae 147 1.01 Websterinereis tridentata 94 1.90 Pycnogonum cessaci 106 0.73 Syllis and Haplosyllis sp. 91 1.84 Cymadusa sp. 105 0.72 Undet. Actiniaria 81 1.64 Synalpheus townsendi 96 0.66 Undet. Sipuncula 77 1.56 Hesionidae sp. A 94 0.65 Dulichiella sp. 73 1.48 Lumbrineris inflata 76 0.52 Lumbrineris inflata 61 1.23 Megalobrachium soriatum 74 0.51 Hesionidae sp. A 51 1.03 Hiatella arctica 62 0.43 Undet. Anamixidae 47 0.95 Lithophaga bisulcata 57 0.39

86

Table 6. Rank by abundance of the top 25 most abundant species in samples collected from Julian’s Ledge in 2005.

% of Julian's Ledge Abundance Total Syllis and Haplosyllis sp. 807 14.65 Ophiactis algicola 417 7.57 Timoclea grus 234 4.25 Elasmopus sp. 233 4.23 Undet. Aspidosiphoniformes 233 4.23 Undet. Sipuncula (other orders) 211 3.83 Undet. Terebellidae 186 3.38 Ophiactis savignyi 173 3.14 Gammaropsis sp. 149 2.71 Undet. Nemertea 149 2.71 Lumbrineris inflata 134 2.43 Chama congregata 123 2.23 Undet. Sabellidae 87 1.58 Gregariella coralliophaga 85 1.54 Eunice filamentosa 83 1.51 Megalobrachium soriatum 75 1.36 Hiatella arctica 73 1.33 Undet. Capitellidae 70 1.27 Amphipholis squamata 69 1.25 Liljeborgia sp. 68 1.23 Eunice sp. A 67 1.22 Synalpheus townsendi 55 1.00 Pagurus carolinensis 53 0.96 Cymadusa sp. 50 0.91 Undet. Nebaliopsididae 46 0.84

87

Table 7. Overall rank by frequency of occurrence (%) of major sessile taxa occurring in 10 or more samples collected from Area 53, Area 51, and Julian’s Ledge in 2005.

Frequency of Occurrence Species Count of Collections (%) Balanus trigonus 70 100.00 Sertularella conica 37 52.86 Clathrina sp. 32 45.71 Crisulipora orientalis 29 41.43 Bugula fulva 27 38.57 Schizoporella unicornis 22 31.43 Dynamena quadridentata 21 30.00 Eudendrium carneum 21 30.00 Thyroscyphus marginatus 20 28.57 Tricellaria sp. A 20 28.57 Filograna implexa 19 27.14 Monostaechas quadridens 19 27.14 Undet. Chaetopteridae 19 27.14 Didemnum candidum 19 27.14 Trididemnum savignii 18 25.71 Undet. Demospongiae sp. E 18 25.71 Chaperia sp. A 17 24.29 Amathia vidovici 15 21.43 Schizoporella violacea 14 20.00 Tetraplaria dichotoma 13 18.57 Dynamena cornicina 12 17.14 Spongiidae sp. A 11 15.71 Corydendrium parasiticum 10 14.29 Halecium tenellum 10 14.29 Mycale sp. 10 14.29

88

Table 8. Rank by frequency of occurrence (%) of the top 25 most frequently occurring sessile species in samples collected from Area 53 (A53) and Area 51 (A51) during 2005.

Occurrence Occurrence A53 (%) A51 (%) Balanus trigonus 100.00 Balanus trigonus 100.00 Sertularella conica 86.36 Eudendrium carneum 83.33 Tricellaria sp. A 77.27 Monostaechas quadridens 79.17 Trididemnum savignii 63.64 Sertularella conica 75.00 Bugula fulva 54.55 Bugula fulva 54.17 Didemnum candidum 50.00 Amathia vidovici 54.17 Mycale sp. 45.45 Corydendrium parasiticum 41.67 Schizoporella unicornis 40.91 Undet. Demospongiae sp. E 37.50 Undet. Demospongiae sp. E 40.91 Crisulipora orientalis 29.17 Halecium tenellum 40.91 Schizoporella unicornis 29.17 Clathrina sp. 36.36 Dynamena cornicina 29.17 Aplidium stellatum (?) 31.82 Bugula neritina 29.17 Clytia linearis 31.82 Halocordyle disticha 29.17 Eusynstyela floridana 27.27 Undet. Petrosina 25.00 Leucetta sp. 27.27 Lissodendoryx sp. 20.83 Dynamena cornicina 22.73 Molgula occidentalis 20.83 Spongiidae sp. A 22.73 Clathrina sp. 16.67 Leucosolenida sp. A 22.73 Dynamena quadridentata 16.67 Undet. Chondropsidae 22.73 Didemnum candidum 16.67 Symplegma viride 18.18 Trididemnum savignii 16.67 Obelia dichotoma 18.18 Spongiidae sp. A 16.67 Dynamena quadridentata 13.64 Bugula turrita 16.67 Leucosolenida sp. B 13.64 Caulibugula pearsei 16.67 Beania mirabilis 13.64 Symplegma viride 12.50 Spongia sp. 12.50

89

Table 9. Rank by frequency of occurrence (%) of the top 25 most frequently occurring sessile species in samples collected from Julian’s Ledge during 2005.

Occurrence Julian’s Ledge (%) Balanus trigonus 100.00 Crisulipora orientalis 91.67 Clathrina sp. 83.33 Thyroscyphus marginatus 83.33 Filograna implexa 79.17 Undet. Chaetopteridae 79.17 Chaperia sp. A 70.83 Dynamena quadridentata 58.33 Schizoporella violacea 58.33 Tetraplaria dichotoma 54.17 Ciocalypta sp. 37.50 Turbicellepora dichotoma 33.33 Arthropoma cecilii 33.33 Eudistoma carolinense 33.33 Leucosolenida sp. C 29.17 Microporella sp. A 29.17 Petraliella bisinuata 29.17 Schizoporella unicornis 25.00 Scypha sp. 25.00 Leucosolenida sp. E 25.00 Ircinia felix 25.00 Cinachyra sp. 20.83 Thesea nivea 20.83 Didemnum candidum 16.67 Craniella sp. 16.67 Ectoprocta sp. A 16.67 Fangophilina sp. 16.67 Halichondrida sp. A 16.67 Parasmittina spathulata 16.67

90 Table 10. Species groups resulting from inverse Canberra metric cluster analysis of samples collected from Area 53, Area 51, and Julian’s Ledge during 2005 (Am = Amphipoda; Bi = Bivalvia; D = Decapoda; E = Echinodermata; G = Gastropoda; I = Isopoda; Mx = Maxillopoda; P = Polychaeta; Ph = Phyllocarida; Py = Pycnogonida; S = Sipuncula; Ta = Tanaidacea).

Group A Group B Ampelisca sp. (Am) Caprella penantis (Am) Proceraea sp. (P) Hornellia tequestae (Am) Periclimenes iridescens (D) Undet. Actiniaria Turbonilla sp. A (G) Diplodonta punctata (Bi) Websterinereis tridentata (P) Barbatia domingensis (Bi) Undet. Leptocheliidae (Ta) Pagurus carolinensis (D) Kochlorine floridana (Mx) Maera sp. (Am) Timoclea grus (Bi) Synelmis sp. (P) Colomastix sp. (Am) Undet. Capitellidae (P) Eunice sp. A (P) Pycnogonum cessaci (Py) Gastrochaena hians (Bi) Ophiostigma isocanthum (E) Hypsicomus sp. (G) Undet. Cirratulidae (P) Undet. Nebaliopsididae (Ph) Lithophaga bisulcata (Bi) Micropanope nuttingi (D) Amphipholis januarii (E) Odontosyllis fulgurans (P) Polynoidae sp. B (P) Paracerceis caudata (I) Undet. Aoridae (Am) Prionospio sp. (P) Group C Pherusa sp. A (P) Eunice filamentosa (P) Dendostrea frons (Bi) Nicon sp. A (P) Ophiactis savignyi (E) Polynoidae sp. A (P) Trypanosyllis zebra (P) Marshallora nigrocincta (G) Dulichiella sp. (Am) Spirobranchus giganteus (P) Synalpheus minus (D) Group E Cumingia coarctata (Bi) Vitrinellidae sp. A (G) Gregariella coralliophaga (Bi) Brania sp. (P) Undet. Trematoda Joeropsis coralicola (I) Marginellidae sp. A (Bi) Lithophaga bisulcata (Bi) Maldanidae sp. B (P) Group D Undet. Aspidosiphoniformes (S) Pandora sp. A (Bi) Carpias bermudensis (I) Undet. Nemertea Liljeborgia sp. (Am) Ericthonius brasiliensis (Am) Ophiactis algicola (E) Pterocirrus macrocerus (P) Stenothoe sp. (Am) Mithraculus forceps (D) Pseudomedaeus agassizii (D) Group F Amphipholis squamata (E) Leucothoe spinicarpa (Am) Deutella incerta (Am) Arca zebra (Bi) Chama congregata (Bi) Megalomma sp. (P) Thyone pseudofusus (E) Undet. Sipuncula (S) Microjassa tetradonta (Am) Autolytus sp. (P) Undet. Terebellidae (P) Photis sp. (Am) Stramonita haemastoma floridana (G) Elasmopus sp. (Am) Latreutes parvulus (D) Diodora cayenensis (G) Lumbrineris inflata (P) Pilumnus dasypodus (D) Nereiphylla fragilis (P) Syllis and Haplosyllis sp. (P) Undet. Turbellaria Parapinnixa hendersoni (D) Cymadusa sp. (Am) Musculus lateralis (Bi) Ampithoe sp. (Am) Hesionidae sp. A (P) Undet. Anamixidae (Am) Chama macerophylla (Bi) Polydora sp. (P) Thor manningi (D) Lysidice ninetta (P) Eunice antennata (P) Podocerus sp. (Am) Astyris lunata (G) Spio sp. (P) Pododesmus rudis (Bi) Cerithiopsis greenii (G) Hiatella arctica (Bi) Nassarina glypta (G) Gammaropsis sp. (Am) Group G Costoanachis avara (G) Megalobrachium soriatum (D) Eulalia sanguinea (P) Ophiothrix angulata (E) Pectinariidae sp. A (P) Synalpheus townsendi (D) Pelia mutica (D)

91 Table 11. Species groups resulting from inverse Jaccard similarity analysis of samples collected from Area 53, Area 51, and Julian’s Ledge during 2005 (Am = Amphipoda; As = Ascidiacea; Bi = Bivalvia; Br = Brachiopoda; D = Decapoda; E = Echinodermata; Ec = Ectoprocta; G = Gastropoda; Hy = Hydrozoa; I = Isopoda; Mx = Maxillopoda; My = Mysida; N = Nudibranchia; O = Octocorallia; P = Polychaeta; Ph = Phyllocarida; Po = Porifera; Py = Pycnogonida; S = Sipuncula; St = Stomatopoda, Ta = Tanaidacea).

Group A

Undet. Terebellidae (P) Gastrochaena hians (Bi) Caprella penantis (Am) Websterinereis tridentata (P) Undet. Nemertea Eudendrium carneum (Hy) Balanus trigonus (Mx) Joeropsis coralicola (I) Lissodendoryx sp. (Po) Undet. Capitellidae (P) Lithophaga bisulcata (Bi) Halocordyle disticha (Hy) Undet. Sipuncula (S) Undet. Aspidosiphoniformes (S) Monostaechas quadridens (Hy) Timoclea grus (Bi) Nicon sp. A (P) Corydendrium parasiticum (Hy) Undet. Actiniaria Trypanosyllis zebra (P) Colomastix sp. (Am) Syllis and Haplosyllis sp. (P) Eulalia sanguinea (P) Spongia sp. (Po) Synalpheus townsendi (D) Pelia mutica (D) Lysianopsis alba (Am) Proceraea sp. (P) Latreutes parvulus (D) Amathia vidovici (Ec) Spio sp. (P) Pilumnus dasypodus (D) Odontosyllis fulgurans (P) Ophiothrix angulata (E) Undet. Turbellaria Lithophaga aristata (Bi) Polydora sp. (P) Deutella incerta (Am) Pycnogonum cessaci (Py) Megalobrachium soriatum (D) Megalomma sp. (P) Hypsicomus sp. (P) Micropanope nuttingi (D) Pseudomedaeus agassizii (D) Hiatella arctica (Bi) Sertularella conica (Hy) Group C Lumbrineris inflata (P) Undet. Demospongiae sp. E (Po) Gammaropsis sp. (Am) Photis sp. (Am) Sertularella unituba (Hy) Hesionidae sp. A (P) Dynamena cornicina (Hy) Leucosolenida sp. A (Po) Elasmopus sp. (Am) Microjassa tetradonta (Am) Eunice antennata (P) Trididemnum savignii (As) Group D Chama congregata (Bi) Doto sp. (N) Cymadusa sp. (Am) Undet. Anamixidae (Am) Bugula uniserialis (Ec) Carpias bermudensis (I) Didemnum candidum (As) Astyris lunata (Bi) Clathrina sp. (Po) Podocerus sp. (Am) Schizoporella unicornis (Ec) Tricellaria sp. A (Ec) Group E Polynoidae sp. B (P) Spongiidae sp. A (Po) Undet. Aoridae (Am) Musculus lateralis (Bi) Mithrax hispidus (D) Pagurus carolinensis (D) Thor manningi (D) Parapinnixa hendersoni (D) Ericthonius brasiliensis (Am) Marphysa sp. A (P) Nereiphylla fragilis (P) Stenothoe sp. (Am) Pectinariidae sp. A (P) Alderina sp. A (Ec) Bugula fulva (Ec) Arca imbricata (Bi) Pherusa sp. A (P) Group B Gemmotheres chamae (D) Leucothoe spinicarpa (Am) Pododesmus rudis (Bi) Diplodonta punctata (Bi) Group F Ophiactis algicola (E) Undet. Leptocheliidae Dynamena quadridentata (Hy) Maera sp. (Am) Vermiliopsis annulata (P) Undet. Cirratulidae (P) Periclimenes iridescens (D) Scalibregmatidae sp. A (P)

92

Table 11. Continued.

Group F (continued)

Pteria colymbus (Bi) Marshallora nigrotincta (G) Ircinia felix (Po) Conopea merrilli (Mx) Modiolus americanus (Bi) Kochlorine floridana (Mx) Chama macerophylla (Bi) Crepidula aculeata (G) Filograna implexa (P) Undet. Cumacea Gonodactylus bredini (St) Hornellia tequestae (Am) Craniella sp. (Po) Eunice sp. A (P) Group G Cerithiopsis emersonii (Bi) Exogone sp. (P) Kalliapseudidae sp. (Ta) Eudistoma carolinense (As) Arbacia punctulata (E) Chrysopetalidae sp. B (P) Eunice filamentosa (P) Stenorhynchus seticornis (D) Pitho sp. (D) Barbatia domingensis (Bi) Erichsonella filiformis (I) Amphipholis januarii (E) Chaperia sp. A (Ec) Ampithoe sp. (Am) Ceratoneries mirabilis (P) Arthropoma cecilii (Ec) Aplysilla sulfurea (Po) Macrocoeloma trispinosum (D) Cumingia coarctata (Bi) Microporella sp. A (Ec) Pandora sp. A (Bi) Group H Vitrinellidae sp. B (G) Hyattella sp. (Po) Brania sp. (P) Thyone pseudofusus (E) Anaitides sp. A (P) Maldanidae sp. B (P) Amphipholis squamata (E) Glycera sp. A (P) Marginellidae sp. A (G) Arca zebra (Bi) Undet. Echiura Ciocalypta sp. (Po) Leucosolenida sp. E (Po) Scypha sp. (Po) Gouldia cerina (Bi) Mithraculus forceps (D) Costoanachis avara (G) Cinachyra sp. (Po) Autolytus sp. (P) Cerithiopsis greenii (G) Crisulipora orientalis (Ec) S. haemastoma floridana (G) Nassarina glypta (G) Diodora cayenensis (G) Gregariella coralliophaga (Bi) Turbicellepora dichotoma (Ec) Lysidice ninetta (P) Group I Undet. Inarticulata (Br) Parasmittina spathulata (Ec) Leucosolenida sp. C (Po) Trypanosyllis sp. A (P) Pagurus brevidactylus (D) Liljeborgia sp. (Am) Thesea nivea (O) Thracia morrisoni (Bi) Pterocirrus macroceros (P) Undet. Apseudidae (Ta) Malleus candeanus (Bi) Undet. Chaetopteridae (P) Arcopsis adamsi (Bi) Natacidae sp. A (G) Undet. Nebaliopsididae (Ph) Microphrys antillensis (D) Boonea seminuda (G) Ampelisca sp. (Am) Scrupocellaria regularis (Ec) Cantharus multangulus (G) Thyroscyphus marginatus (Hy) Fangophilina sp. (Po) Diplodonta semiaspera (Bi) Turbonilla sp. A (G) Processa sp. (D) Ectoprocta sp. A (Ec) Synelmis sp. (P) Amphiura sp. A (E) Halichondrida sp. A (Po) Tetraplaria dichotoma (Ec) Rullerinereis sp. A (P) Anchialina typica (My) Prionospio sp. (P) Parasmittina trispinosa (Ec) Schizoporella violacea (Ec) Group J Spirobranchus giganteus (P) Paracerceis caudata (I) Chicoreus pomum (G) Petraliella bisinuata (Ec) Synalpheus minus (D) Mytilidae sp. A (Bi) Ophiactis savignyi (E) Leucosolenida sp. B (Po) Paguristes tortugae (D) Ophiostigma isocanthum (E) Vitrinellidae sp. A (G)

93

Table 11. Continued.

Group J (continued)

Typton sp. A (D) Aplidium stellatum? (As) Periclimenes americanus (D) Pilumnus sayi (D) Achelia sawayai (Py) Limnotheres nasutus (D) Ircinia strobilina (Po) Eusynstyela floridana (As) Facelina sp. (N) Undet. Trematoda Neopontonides beaufortensis (D) Beania mirabilis (Ec) Caulibugula pearsei (Ec) Molgula occidentalis (As) Undet. Petrosina (Po) Amblyosyllis formosa (P)

Group G

Chrysopetalidae sp. A (P)

Group H

Bugula turrita (Ec) Bugula neritina (Ec) Obelia dichotoma (Hy) Tumidotheres maculatus (D) Leucosolenia sp. (Po) Lumbrineridae sp. A (P) Parvilucina multilineata (Bi) Dendostrea frons (Bi) Doridacea sp. B (N) Polycera chilluna (N) Aeolidacea sp. A (N) Doridacea sp. A (N) Mycale sp. (Po) Polynoidae sp. A (P) Turritopsis nutricula (Hy) Symplegma viride (As) Undet. Chondropsidae (Po) Dulichiella sp. (Am) Halecium tenellum (Hy) Clytia linearis (Hy) Pomatoceros sp. A (P) Leucetta sp. (Po) Ostreidae sp. A (Bi)

94

Table 12. Results of Components of Variance analysis, showing contribution of percent variance among reef stations, and percent variance due to error, to total variance.

Variable n s SR biomass H´ J´ Variance - station (%) 9.8 50.7 49.8 8.3 22.3 23.5 Variance - error (%) 90.2 49.3 50.2 91.7 77.7 76.5

95

APPENDICES

96 Appendix A. List of species collected from each sampling site during 2005.

Area 53 Area 51 Julian’s Ledge Amphipoda Americorophium sp. x x Ampelisca sp. x Ampithoe sp. x x Caprella penantis x x x Colomastix sp. x x Cymadusa sp. x x x Deutella incerta x x x Dulichiella sp. x x x Elasmopus sp. x x x Ericthonius brasiliensis x x x Gammaropsis sp. x x x Hornellia tequestae x x Leucothoe spinicarpa x x x Liljeborgia sp. x x Lysianopsis alba x x Maera sp. x x Microjassa tetradonta x x Photis sp. x x Podocerus sp. x x x Stenothoe sp. x x x Undet. Amphilochidae x Undet. Anamixidae x x x Undet. Aoridae x x x Undet. Eusiridae x Undet. Iphimediidae x

Anthozoa Leptogorgia cardinalis x Oculina arbuscula x Telesto fruticulosa x Thesea nivea x Undet. Actiniaria x x x Undet. Zoanthidia x

Ascidiacea Aplidium sp. x x

97 Aplidium stellatum (?) x x Clavelina sp. x Didemnidae sp. A x Didemnum candidum x x x Eudistoma carolinense x Eusynstyela floridana x x Molgula occidentalis x Pyura vittata x Styelidae sp. A x Symplegma viride x x Trididemnum savignii x x Undet. Ascidiacea - colonial x x x Undet. Ascidiacea - solitary x x x

Bivalvia Americardia media x Arca imbricata x x Arca zebra x x Arcopsis adamsi x Barbatia candida x Barbatia domingensis x Chama congregata x x x Chama macerophylla x x x Chama sp. A x x Crassinella lunulata x Cumingia coarctata x x Dendostrea frons x x x Diplodonta punctata x x Diplodonta semiaspera x x Gastrochaena hians x x x Gouldia cerina x Gregariella coralliophaga x x x Hiatella arctica x x x Isognomon radiatus x Lithophaga aristata x x Lithophaga bisulcata x x x Lyonsiidae sp. A x Malleus candeanus x Modiolus americanus x Musculus lateralis x x x

98 Mytilidae sp. A x Nuculana sp. A x Ostrea equestris x Ostreidae sp. A x x Pandora sp. A x x Parvilucina multilineata x x Plicatula gibbosa x Pododesmus rudis x x x Pteria colymbus x x Thracia morrisoni x Timoclea grus x x x Undet. Bivalvia x x x

Cumacea Undet. Cumacea x x x

Decapoda Alpheus formosus x Alpheus normanni x Alpheus sp. x Anchistioides antiguensis x Gemmotheres chamae x x x Hippolyte obliquimanus x Hippolyte sp. x Hippolyte zostericola x Latreutes fucorum x Latreutes parvulus x x x Leptochela papulata x Lucifer faxoni x Macrocoeloma trispinosum x x Megalobrachium soriatum x x x Micropanope nuttingi x x x Micropanope sp. x x x Microphrys antillensis x x Mithraculus forceps x x Mithrax hispidus x x Mithrax pleuracanthus x x Mithrax sp. x x x Munida sp. A x x Neopontonides beaufortensis x x

99 Paguristes sp. A x Paguristes tortugae x Pagurus brevidactylus x Pagurus carolinensis x x x Parapinnixa hendersoni x x Pelia mutica x x x Periclimenaeus sp. x Periclimenes americanus x x x Periclimenes iridescens x x Periclimenes sp. x Petrolisthes galathinus x Pilumnus dasypodus x x x Pilumnus sayi x x x Pilumnus sp. x x x Pinnixa chaetopterana x Limnotheres nasutus x Pitho sp. x Podochela gracilipes x x Podochela sidneyi x Processa sp. x Pseudomedaeus agassizii x x x Sicyonia laevigata x x Speloeophorus pontifer x Stenocionops furcatus coelata x x Stenocionops sp. x Stenorhynchus seticornis x x Synalpheus fritzmuelleri x Synalpheus minus x x x Synalpheus sp. x x x Synalpheus townsendi x x x Thor dobkini x x Thor manningi x x x Thor sp. x Tumidotheres maculatus x x Typton sp. A x x x Undet. Brachyura x x x Undet. Caridea x x Undet. Pinnotheridae x Zaops ostreum x x

100 Echinoidea Arbacia punctulata x

Echiura Undet. Echiura x x

Ectoprocta Aeverrillia setigera x x Alderina sp. A x x Amathia vidovici x x Arthropoma cecilii x Beania hirtissima x Beania mirabilis x Bugula fulva x x x Bugula neritina x x Bugula turrita x Bugula uniserialis x Caberea boryi x Caulibugula pearsei x Caulibugula sp. x Celleporaria magnifica x Chaperia sp. A x Crisulipora orientalis x x Diaperoecia floridana x Ectoprocta sp. A x Hippoliosina rostrigera x Hippopleurifera mucronata x x Hippoporina contracta x Lichenopora radiata x Microporella sp. A x Parasmittina spathulata x Parasmittina trispinosa x Petraliella bisinuata x Reptadeonella costulata x Rhynchozoon rostratum x Schizoporella unicornis x x x Schizoporella violacea x Scrupocellaria regularis x Tetraplaria dichotoma x Tricellaria sp. A x x x

101 Turbicellepora dichotoma x x

Gastropoda Aeolidacea sp. A x Aeolidacea sp. B x Aeolidacea sp. C x Aeolidacea sp. D x Aeolidacea sp. E x Aeolidacea sp. F x Aeolidacea sp. G x Aeolidacea sp. H x Astyris lunata x x x Boonea seminuda x Cantharus multangulus x x Cerithiopsis emersonii x x Cerithiopsis greenii x x Cerithiopsis sp. A x Cerithium atratum x Chicoreus pomum x Costoanachis avara x x x Crepidula aculeata x Crepidula plana x Diodora cayenensis x x Doridacea sp. A x Doridacea sp. B x Doridacea sp. C x Doridacea sp. D x x Doridacea sp. E x Doto sp. x x x Facelina sp. x x Marginellidae sp. A x Marshallora nigrotincta x x Melanella jamaicensis x Melanella sp. A x Muricidae sp. A x Nassarina glypta x x Natacidae sp. A x Odostomia sp. A x Olivella mutica x Pollia tincta x x

102 Polycera chilluna x Seila adamsi x x Stramonita haemastoma floridana x x x Terebra dislocata x Trachypollia nodulosa x Triphora triserialis x Turbo castanea x Turbonilla sp. A x x Turridae sp. A x Undet. Aeolidacea x x Undet. Prosobranchia x Vexillum sykesi x Vitrinellidae sp. A x x x Vitrinellidae sp. B x

Holothuroidea Istichopus badionotus x Ocnus pygmaeus x Thyone deichmannae x Thyone pseudofusus x x

Hydroida Bougainvillia muscus x Campanularia hincksii x Clytia linearis (?) x Clytia noliformis (?) x Corydendrium parasiticum x Dynamena cornicina x x Dynamena quadridentata x x x Eudendrium carneum x x Eudendrium sp. x x Halecium tenellum x x Halocordyle disticha x Macrorhynchia allmani x Monostaechas quadridens x Obelia dichotoma x x Plumularia setacea x Sertularella conica x x Sertularella unituba x x x Thyroscyphus marginatus x

103 Turritopsis nutricula x x

Inarticulata Undet. Inarticulata x x

Isopoda Arcturella spinata x Arcturidae sp. A x Carpias bermudensis x x x Carpias minutus x Carpias sp. A x Edotia triloba x Erichsonella filiformis x x Joeropsis coralicola x x x Paracerceis caudata x x Undet. Anthuridae x Undet. Bopyridae x Undet. Gnathiidae x

Maxillopoda Balanus trigonus x x x Conopea merrilli x x x Copepoda - Harpacticoida x x Kochlorine floridana x

Mysidacea Anchialina typica x x

Ophiuroidea Amphipholis januarii x Amphipholis squamata x x Amphiura sp. A x Ophiactis algicola x x x Ophiactis savignyi x Ophiocominae sp. A x Ophioderma appressum x Ophiopsila riisei x Ophiostigma isocanthum x Ophiothrix angulata x x x Undet. Ophiuroidea x

104

Nemertea Undet. Nemertea x x x

Phyllocarida Undet. Nebaliopsididae x

Polychaeta Amblyosyllis formosa x Anaitides sp. A x x Aphroditidae sp. A x x Aphroditidae sp. B x Autolytus sp. x x x Brania sp. x Ceratoneries mirabilis x Chone sp. A x Chrysopetalidae sp. A x x Chrysopetalidae sp. B x Eulalia sanguinea x x x Eunice antennata x x x Eunice filamentosa x Eunice sp. A x Exogone sp. x x Filograna implexa x Glycera sp. A x x x Hesionidae sp. A x x x Hypsicomus sp. x x Laonice cirrata x x Lumbrineridae sp. A x x Lumbrineris inflata x x x Lysidice ninetta x x x Maldanidae sp. A x x Maldanidae sp. B x Marphysa sp. A x x x Megalomma sp. x x x Neanthes sp. A x Nereiphylla fragilis x x x Nereis riisei x Nicon sp. A x x x Odontosyllis fulgurans x x

105 Oenonidae sp. A x Paranaitis sp. A x Pectinariidae sp. A x x x Pherusa sp. A x x x Polydora sp. x x x Polynoidae sp. A x x Polynoidae sp. B x x x Pomatoceros sp. A x x Prionospio sp. x Proceraea sp. x x x Pseudovermilia occidentalis x Pterocirrus macroceros x x Rullerinereis sp. A x x x Scalibregmatidae sp. A x x Serpulidae sp. A x Spio sp. x x x Spirobranchus giganteus x Syllis and Haplosyllis sp. x x x Synelmis sp. x Trypanosyllis sp. A x Trypanosyllis zebra x x x Undet. Capitellidae x x x Undet. Chaetopteridae x Undet. Cirratulidae x x x Undet. Eunicidae x Undet. Nereididae x x Undet. Phyllodocidae x x Undet. Polychaeta x x x Undet. Sabellidae x x x Undet. Serpulidae x x Undet. Syllidae x Undet. Terebellidae x x x Vermiliopsis annulata x x Websterinereis tridentata x x x Xenosyllis sp. x

Porifera Aplysilla sulfurea x Aplysina sp. x Axinella bookhouti x

106 Axinella polycapella x Chelonaplysilla erecta x Cinachyra sp. x Ciocalypta sp. x Clathrina sp. x x x Cliona sp. x Craniella sp. x Dysidea fragilis x Dysidea (?) sp. x Fangophilina sp. x Geodia sp. x Halichondrida sp. A x Haliclona (?) sp. B x Hyattella sp. x x Ircinia felix (?) x Ircinia strobilina (?) x x Leucetta sp. x Leucosolenia sp. x x Leucosolenida sp. A x x x Leucosolenida sp. B x x x Leucosolenida sp. C x x Leucosolenida sp. D x Leucosolenida sp. E x x Lissodendoryx sp. x x x Microciona prolifera x Mycale sp. x Samus anonymus x Scypha sp. x x Spongia sp. x Spongiidae sp. A x x x Undet. Ancorinidae (?) x Undet. Calcarea x Undet. Chondropsidae (?) x x Undet. Demospongiae x x x Undet. Demospongiae sp. A x Undet. Demospongiae sp. B x Undet. Demospongiae sp. C x Undet. Demospongiae sp. D x Undet. Demospongiae (?) sp. E x x Undet. Dictyoceratida x

107 Undet. Hemiasterellidae x Undet. Leucosolenida x x x Undet. Niphatidae (?) x Undet. Pachastrellidae x Undet. Petrosina x x Undet. Poecilosclerida x Undet. Suberitidae (?) x Undet. Tethyidae x

Pycnogonida Achelia sawayai x x x Achelia sp. A x Anoplodactylus lentus x Ascorhynchus sp. A x Pycnogonum cessaci x x Undet. Ammotheidae

Sipuncula Undet. Aspidosiphoniformes x x x Undet. Sipuncula (other orders) x x x

Stomatopoda Gonodactylus bredini x Gonodactylus sp. x

Tanaidacea Undet. Apseudidae x Undet. Kalliapseudidae x Undet. Leptocheliidae x x

Turbellaria Undet. Turbellaria x x x

Trematoda Undet. Trematoda x

Undet. Phyla x x x

108

Appendix B. List of meifaunal or pelagic organisms collected during spring/summer 2005.

Scientific Name A53 A51 NR Copepoda - Calanoida x x Copepoda - Cyclopoida x x Ostracoda sp. A x Ostracoda sp. B x x Ostracoda sp. C x Ostracoda sp. D x Ostracoda sp. E x Ostracoda sp. F x Sarsiellidae sp. A x Sarsiellidae sp. B x Undet. Myodocopida x Undet. Nemata x x x

109

Appendix C. List of species collected exclusively from Area 53’s northeast and northwest corners during April 2006.

Species A53-NE A53-NW Ascidia sp. A x Genetyllis castanea x x Haliclona sp. A x Hypselodoris edenticulata x Inachoides forceps x Lima sp. A x Lindapecten muscuosus x Metoporhaphis calcarata x Pachycheles rugimanus x Pagurus sp. x Pilumnus floridanus x Polynoidae sp. C x Polynoidae sp. D x Smittina sp. A x Undet. Ammotheidae x Undet. Clathrinida x Undet. Xanthidae x

110

Appendix D. Lists of species collected exclusively from Area 53 and Area 51 during 2005.

Area 53 Area 51 Aeolidacea sp. A Achelia sp. A Aeolidacea sp. B Aeolidacea sp. G Aeolidacea sp. C Aeolidacea sp. H Aeolidacea sp. D Amblyosyllis formosa Aeolidacea sp. E Bugula turrita Aeolidacea sp. F Campanularia hincksii Anchistioides antiguensis Carpias minutus Beania mirabilis Caulibugula pearsei Bougainvillia muscus Corydendrium parasiticum Clytia linearis Doridacea sp. C Clytia noliformis Dysidea fragilis Doridacea sp. A Halocordyle disticha Doridacea sp. B Hippolyte obliquimanus Isognomon radiatus Hippolyte zostericola Leptochela papulata Latreutes fucorum Leucetta sp. Molgula occidentalis Leucosolenida sp. D Monostaechas quadridens Neanthes sp. A Oculina arbuscula Paranaitis sp. A Olivella mutica Limnotheres nasutus Pinnixa chaetopterana Plumularia setacea Plicatula gibbosa Podochela sidneyi Spongia sp. Polycera chilluna Synalpheus fritzmuelleri Pyura vittata Turbo castanea Terebra dislocata Undet. Eusiridae Undet. Trematoda Undet. Suberitidae Undet. Zoanthidia

111 Appendix E. List of species collected exclusively from Julian’s Ledge during 2005.

Julian's Ledge

Alpheus formosus Chrysopetalidae sp. B Lyonsiidae sp. A Alpheus normanni Cinachyra sp. Macrorhynchia allmani Americardia media Ciocalypta sp. Maldanidae sp. B Ampelisca sp. Clavelina sp. Malleus candeanus Amphipholis januarii Cliona sp. Marginellidae sp. A Amphiura sp. A Craniella sp. Melanella jamaicensis Anoplodactylus lentus Crassinella lunulata Melanella sp. A Aphroditidae sp. B Crepidula aculeata Microciona prolifera Aplysilla sulfurea Crepidula plana Microporella sp. A Aplysina sp. Diaperoecia floridana Modiolus americanus Arbacia punctulata Didemnidae sp. A Muricidae sp. A Arcopsis adamsi Doridacea sp. E Mytilidae sp. A Arcturella spinata Ectoprocta sp. A Natacidae sp. A Arcturidae sp. A Edotia triloba Nereis riisei Arthropoma cecilii Eudistoma carolinense Nuculana sp. A Ascorhynchus sp. A Eunice filamentosa Ocnus pygmaeus Axinella bookhouti Eunice sp. A Odostomia sp. A Axinella polycapella Fangophilina sp. Oenonidae sp. A Barbatia candida Filograna implexa Ophiactis savignyi Barbatia domingensis Geodia sp. Ophiocominae sp. A Beania hirtissima Gonodactylus bredini Ophioderma appressum Boonea seminuda Gouldia cerina Ophiopsila riisei Brania sp. Halichondrida sp. A Ophiostigma isocanthum Caberea boryi Haliclona sp. B Ostrea equestris Carpias sp. A Hippoliosina rostrigera Paguristes sp. A Celleporaria magnifica Hippoporina contracta Paguristes tortugae Ceratoneries mirabilis Ircinia felix Pagurus brevidactylus Cerithiopsis sp. A Istichopus badionotus Parasmittina spathulata Cerithium atratum Kalliapseudidae sp. Parasmittina trispinosa Chaperia sp. A Kochlorine floridana Periclimenaeus sp. Chelonaplysilla erecta Leptogorgia cardinalis Petraliella bisinuata Chicoreus pomum Lichenopora radiata Petrolisthes galathinus Chone sp. A Lucifer faxoni Pitho sp.

112

Appendix E. Continued.

Julian’s Ledge Prionospio sp. Undet. Demospongiae sp. A Processa sp. Undet. Demospongiae sp. B Pseudovermilia occidentalis Undet. Demospongiae sp. C Reptadeonella costulata Undet. Demospongiae sp. D Rhynchozoon rostratum Undet. Gnathiidae Samus anonymus Undet. Hemiasterellidae Schizoporella violacea Undet. Iphimediidae Scrupocellaria regularis Undet. Nebaliopsididae Serpulidae sp. A Undet. Niphatidae Speloeophorus pontifer Undet. Pachastrellidae Spirobranchus giganteus Undet. Tethyidae Styelidae sp A Vexillum sykesi Synelmis sp. Vitrinellidae sp. B Telesto fruticulosa Xenosyllis sp. Tetraplaria dichotoma Thesea nivea Thracia morrisoni Thyone deichmannae Trachypollia nodulosa Triphora triserialis Trypanosyllis sp. A Turridae sp. A Undet. Amphilochidae Undet. Ancorinidae Undet. Anthuridae Undet. Apseudidae Undet. Bopyridae Undet. Chaetopteridae

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Appendix F. List of species common to Area 53, Area 51, and Julian’s Ledge during 2005.

Achelia sawayai Hiatella arctica Proceraea sp. Amathia vidovici Joeropsis coralicola Pseudomedaeus agassizii Astyris lunata Latreutes parvulus Rullerinereis sp. A Autolytus sp. Leucosolenida sp. A Schizoporella unicornis Balanus trigonus Leucosolenida sp. B Sertularella unituba Bugula fulva Leucosolenida sp. E Spio sp. Caprella penantis Leucothoe spinicarpa Spongiidae sp. A Carpias bermudensis Lissodendoryx sp. Stenothoe sp. Chama congregata Lithophaga bisulcata Stramonita haemastoma floridana Chama macerophylla Lumbrineris inflata Syllis and Haplosyllis sp. Clathrina sp. Lysidice ninetta Synalpheus minus Conopea merrilli Marphysa sp. A Synalpheus townsendi Costoanachis avara Megalobrachium soriatum Thor manningi Crisulipora orientalis Megalomma sp. Timoclea grus Cymadusa sp. Micropanope nuttingi Tricellaria sp. A Dendostrea frons Musculus lateralis Trypanosyllis zebra Deutella incerta Nereiphylla fragilis Typton sp. A Didemnum candidum Nicon sp. A Undet. Actiniaria Doto sp. Ophiactis algicola Undet. Anamixidae Dulichiella sp. Ophiothrix angulata Undet. Aoridae Dynamena quadridentata Pagurus carolinensis Undet. Aspidosiphoniformes Elasmopus sp. Pectinariidae sp. A Undet. Capitellidae Ericthonius brasiliensis Pelia mutica Undet. Cirratulidae Eulalia sanguinea Periclimenes americanus Undet. Cumacea Eunice antennata Pherusa sp. A Undet. Nemertea Gammaropsis sp. Pilumnus dasypodus Undet. Sipuncula Gastrochaena hians Pilumnus sayi Undet. Terebellidae Gemmotheres chamae Podocerus sp. Undet. Turbellaria Glycera sp. A Pododesmus rudis Vitrinellidae sp. A Gregariella coralliophaga Polydora sp. Websterinereis tridentata Hesionidae sp. A Polynoidae sp. B

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