WWF Mesoamerican Reef Ecoregion Reef Expedition Report

May 2002

Amigos de Sian Ka’an, Belize Audubon, Coastal Zone Management Institute, DIGEPESCA, Honduran Coral Reef Fund, SEMARNAP, WWF

Executive Summary

The MesoAmerican Reef Caribbean Reef Ecoregion Expedition was conducted over three intervals between September, to November 2001. The expedition was organized by WWF's Mesoamerican Caribbean Reef Program, with the assistance of researchers working with partner organizations (Amigos de Sian Ka’an and SEMARNAP, Mexico; Belize Audubon Society and Coastal Zone Management Institute, Belize; DIGEPESCA and Honduras Coral Reef Fund, Honduras). This expedition represents the first time regional scientists have collaborated on a scientific reef survey of the entire Mesoamerican Reef System. The information obtained will be used to refine the WWF Ecoregional Conservation Plan and to assist local NGOs, government departments, policy makers and affiliated projects in the region with their conservation efforts.

The main goals of the expedition were:

¾ to determine the ecological status of reefs throughout the region ¾ to monitor recovery from the 1998 disturbances (bleaching event and hurricane Mitch) ¾ to give local researchers an ecoregional perspective and training

The study focused on five basic elements of reef communities, which are used to indicate the overall status or health of the ecosystem, including:

1. Reef community structure (percent cover of major functional groups) 2. Scleractinian coral species richness 3. Density of coral recruits / juveniles 4. Coral disease infection rates 5. Percent of recent mortality on corals 6. Sea urchin (Diadema antillarium) density

Overall, the reefs had a mean live coral cover of 15.2%, ranging from 2.6% to 39.7%, although sample sizes and methodology varied due to failure of the video cameras. The average density of recruits/juvenile corals was 7.5/m2, ranging from 1.0 to 14.6/ m2. The average number of stony coral species at each site was 26.7, with a range of 18-33 species. Approximately 3.3 % of the 3,692 corals surveyed had active disease infections, ranging from 0-11.5%. White plague and dark spot diseases were the most common types in the ecoregion, although this varied by sub-region. Dark spot and white band were more common in the northern two sub-regions while black band and white plague were more common in the southern sub-regions. As more is learned about the precise agents and conditions promoting these diseases, these data maybe able to help pinpoint specific impacts in these zones. Overall the mean percent of recent mortality (indicating the percent of each colony that is thought to have died in the last year) in the ecoregion was 1.7%, with a range of 0.2 to 4.4%. The Northern Quintana Roo sub-region contained only three sites, due to the lesser extent of reefs generally in this region and due to logistical constraints with reefs very dispersed. In fact the northernmost site surveyed, at Isla

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Contoy does not fit the criteria of a coral reef, with only 1.7% coral cover. It was not included in any of the mean values.

The Northern Quintana Roo sub-region (two sites in Cozumel) had the highest coral cover (24.5%) and density of recruits / juvenile corals (12.2/m2 ). However the coral species richness (24.5 species per site) was the lowest in the ecoregion. The mean disease infection rate was (about average) 3.0%, with dark spot being the most common disease Corals in this sub-region had the highest recent mortality (2.7%). Because only two true reef sites were surveyed in this sub-region, these data really only represent the condition of Cozumel Island and not the entire sub-region, which has many less developed reefs which are reportedly not in very good condition.

The twelve sites in the Sian-Ka’an/Ambergris sub-region had a live coral cover of 20.3%. and density of recruits / juvenile corals of 7.0 /m2. The average number of coral species was 26.4 per site. The mean disease infection rate was 3.7%, with dark spot being the most common disease. Corals in this sub-region had the lowest percent of recent mortality (1.1%). There was high variability between sites in this sub-region, particularly regarding disease rates and coral cover .

The twelve sites in the Belize Barrier Reef sub-region had a mean coral cover of 12.9%. and density of recruits / juvenile corals was 7.6/m2. The average number of coral species was 26.5 species per site. The mean disease infection rate was 2.3%, with white plague being the most common disease. Corals in this sub-region had an average recent mortality of 1.9%.

The nine sites in the Northern Honduras Coast sub-region had a mean coral cover of 10.1% and density of recruits / juvenile corals was 6.9/m2. This subregion had the highest average number of coral species per site (27.6).The mean disease infection rate was 4.4%, with white plague being the most common disease. Corals in this sub-region had recent mortality of 1.8%.

In summary, we have discovered interesting trends in the ecological status of our reefs by taking this broad ecoregional perspective. In general coral diversity is highest in the south, while coral abundance (adult and juvenile) is higher in the north. This notion that the southern reef represent “source reefs” while the northern reef represent “sink reefs”. While both measures are important to ecosystem health, the relatively low coral cover found in many sites, particularly in the Honduras and Belize sub-regions, is cause for concern. Coral cover ranging from 25-30% would be considered good for the Caribbean. The patterns of coral diseases and recent coral mortality are complex. On average diseases were highest in the N Honduran Coast subregion, and lowest in Belize. Interestingly, Sian-Kaan / Ambergris had high variability in disease levels, potentially indicating the influence of local versus regional stressors (possibly local development), as compared to Honduras, which had consistently high levels, possibly indicating widespread causes (agricultural run-off, etc). Interestingly, while Belize had the lowest average disease rates, it had the relatively high recent mortality, suggesting other causes of mortality (bleaching and hurricane damage). A full community analysis is beyond the

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scope of this expedition report, but the data are available to all participants and others interested in further analysis. The participants agree that the opportunity to study reefs of the entire ecoregion in a relatively short timeframe provided them with invaluable insights and perspective. These data will be valuable for WWF and our partner organizations, for years to come as we monitor the effects of our conservation efforts, particularly the long-term recovery (or lack thereof) from the 1998 disturbances.

Participants List

• Melanie McField.- Coordinator, World Wildlife Fund MACR, Belize • Rosa María Loreto Viruel.- Amigos de Sian Ka’an A. C, Mexico • Roberto Ibarra Navarro.- Parque Nacional Cancún y Pta. Nizuc, Mexico • Felipe Fonseca , Banco Chinchorro Marine Reserve, SEMARNAP, Mexico • Nadia Bood.- Coastal Zone Management Institute, Belize • Sergio Hoare.and Julie Robinson, - Belize Audubon Society, Belize • Marcio Aronne.- Honduras Coral Reef Fund, Honduras • Gillian Osorio.- DIGEPESCA, Honduras

Study Area

Extending over 1000 km, the Mesoamerican Caribbean Reef Ecoregion (MACR) is composed of extensive coral reefs including luxuriant patch, fringing, and barrier reefs and unique offshore atolls. With more than 66 stony coral species and over 500 fish species, this reef system is one of WWF’s highest priority marine ecoregions. Apart from the productive reef resources, the region also has important coastal habitats such as beaches, coastal rivers/lagoons, mangroves, seagrasses, and coastal wetlands that provide important breeding, nesting, and foraging habitat for numerous species.

Within the coastal areas of the MACR lies an array of distinctive community types, organisms, currents, and ecological processes that interact as one functional unit. While some marine environmental factors (temperature and to a lesser degree salinity) are similar within the ecoregion, differences in terrestrial factors such as rainfall, elevation and geology create several distinct subregions within the Ecoregion. The Ecoregion and subregion boundaries were first adjusted to coincide with boundaries of major watersheds on land.

Thirty six sites throughout the ecoregion were visited covering the four sub-regions with significant reefs. (see map). In Belize monitoring sites established for previous monitoring were utilized (McField et al, 2001). These sites were selected to give widest geographic coverage, including reefs under various management strategies and environmental influences (McField et al, 2001). In Mexico, sites were selected to cover the widest geographic range of areas with reported developed reefs, given logistical

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constraints. A several sites also corresponded to existing monitoring sites. In Honduras, sites were selected to provide the widest geographic range of reefs, given logistical constraints. Commercial dive boats and dive sites were used around Roatan and Barbaretta, while an even spatial distribution among the most developed reefs was sought after in Cayos Cochinos.

36 Study Sites Map wih si

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Methods

The sampling scheme utilizes a stratified (windward forereef spurs), haphazard transect- based design, similar to that of several other current monitoring programs (Aronson et al., 1994; Wheaton et al., 1996). Ten replicate 25 m transects are conducted at each site. Transects are oriented along individual reef spurs (or perpendicular to the shelf edge) giving a swath of reef in the zone of greatest reef development. The first benthic transect is “haphazardly” located on the nearest continuous “reef” formation encountered when swimming towards the reef crest from the boat or mooring line. Subsequent transects are laid parallel to the original with approximately 10m between transects (further spacing is better as long as visibility is good and proper dive safety can be maintained). The transects are used to collect the following data:

1. Reef Community Structure. Video transects were designed for this component. However, the Belize Audubon’s housing failed during the first dive of the survey. M. McField’s camera was used for the first 7 sites in Belize, until it also failed. The alternative Linear-point-intercept transect method was then used for the remainder of the study, resulting in fewer numbers of transects and a much lower sample resolution. Thus there is a discrepancy in the overall sampling effort among sites for this parameter. Logistical constraints required that only one dive per site could be conducted.

1.a Video Transects: The video camera is outfitted with a bar to keep the camera at a fixed distance above the substrate, in order to give a swath width of approximately 25 cm. The diver first films a slate with site code and transect number. The diver then begins to film beside the transect line (not filming the line) swimming slowly (5meters/min) holding the camera steady and vertical (perpendicular to the substrate). The camera stops recording at the end of the line and the diver swims to the next spur to video that transect. Seven video transects can be completed per dive (N=7), providing 3500 data points per site.

1.b. Linear Point Intercept Transects (alternate method after video failure): The species or category of benthic organism is recorded for each point falling directly under the mark every 20cm along the 25 meter transect line (giving 125 points per transect). The number of transects collected per site varied with time availability and experience of the data collectors, with maximum of 5 transects per site (giving approximately 625 data points per site).

2. Coral species richness and disease information Three belt surveys (25m x 2m) are conducted along the set transect lines. Coral species presence/absence is recorded for each transect. Each transect requires approximately 15 minutes. Care is taken to search the entire belt area.

3. Coral recruitment (density of recruits / juveniles) Using the same 25m transects, Eight recruitment samples are obtained per site (4 per dive by each of 2 divers). Each sample consists of carefully searching for coral “recruits” within each of eight .5m x .5m quadrats laid along the 25m transect line (at the 4m, 6m,

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8m, 10m, 12m, 14m, 16m, and 18m marks). Recruits are defined as stony corals 10cm and less in size. The species and maximum diameter is recorded for each coral. Branching corals (Porites porites, Acropora cervicornis, etc) are measured along their longest axis (which is usually linearly). Quadrats are laid an the nearest ‘available substrate’ to the indicated transect mark. (thus if the quadrat were to be laid atop a solid massive coral or sponge – the sample location would be moved to the nearest available reef substrate open for recruitment.

4. Coral health status (bleaching, disease infections and partial mortality), WBST Method The “weighted-bar swimming-transect method” was developed as a bleaching assessment by McField (1999) and modified by Kramer and Kramer (2000) to include information on disease and mortality. It utilizes a one meter piece of small diameter PVC tubing filled with stones and capped at both ends (or left open to fill with water). Each bar is marked with five strips of black electrical tape (or other marking) spaced .25 meters apart. Thus there are five marks per bar, including the two ends. The observer swims in a straight line along a compass bearing or depth contour, holding the bar perpendicular to the line of the swimming-transect. Every three kick cycles (one full push down and up for both legs is one kick cycle) the bar is dropped/placed straight down onto the bottom. The species and condition of corals lying under the marks are recorded. Condition refers to that of the overall colony and not to the individual polyps under the mark. If a mark does not fall directly on top of coral, record the condition of the nearest coral colony to the mark which falls within a 12.5 cm radius of the mark. This distance of 12.5 cm is fairly easy to gauge since it is half the distance between any two marks. Thus the bar demarcates five adjacent but non-overlapping circles each centered on a mark. If no coral lies within a given circle no data is recorded for that mark so sandy patches and other non-coral areas can be passed through quickly. For coral bleaching the following categories are used:

• PA=Pale (definite loss off pigment (lighter coloration for that species) • PB=Part Bleached (some white tissue on the colony – not due to other coral diseases such as white band, black band, or white plague) • WB=Wholly Bleached (over 90% white-bleached) tissue

In addition the following diseases are recorded if present: BBD – black band disease, WP=white plague, WB=white band, PB=purple blotch, OD=other disease. The percent of old dead and recently dead coral is also estimated for each colony. Recent dead is identified by coralite structure visible upon scraping the surface clean, as described in AGRA methodology.

5. Urchin Survey: The occurrence of any visible Diadema antillarium along a 2m wide belt along the 25m transect lines is recorded along with data collected for the coral species richness, with some of the recruitment transects, and for some belt transects conducted specifically for urchins, as the time opportunity allows.

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Results Summary

The data are summarized in Table 1 by site and in Table 2 by sub region. A total of 36 sites were surveyed, It was decided that the northernmost site, Isla Contoy, is more a hard bottom or coralline algal ridge than a coral reef, with only 1.7% coral cover and none of the minimal build-up apparently constructed by corals. Thus, it was not included in any of the mean values presented, although it is included in all of the data tables. The Northern Quintana Roo subregion then is more representative of the condition of Cozumel Island than the entire sub-region, which has many less developed reefs.

Table 1. Results Averaged by Site Table 1. Overall Data Summary" WWF 2001 Mesoamerica Reef Survey - by Site

Sub Site coral coral Juvenile coral recent diadema richnes region North to South s cover density disease mortality density # species % cover # /m2 % infected % dead tissue #/m2

o Contoy 2 1.7 0.7 0.0 3.4 0.0000 P. "Bajo" 23 25.1 9.8 4.3 2.3 0.0000

N.Q.Ro Palancar 26 24.0 14.6 1.8 3.2 0.0057

P.Paila 26 25.0 10.1 0.0 1.6 0.0000 P. Yuyum 26 29.3 9.1 1.0 1.4 0.0000

s Mosquitero 22 12.5 8.3 2.9 0.7 0.0000 Coordillara 26 27.6 4.1 3.1 0.2 0.0029 Far Star 26 23.2 2.1 2.3 1.6 0.0000 Canones 31 17.9 1.0 4.5 1.3 0.0000 Mahahual 27 26.3 7.0 1.0 1.0 0.0000 Jomna 26 15.7 11.6 10.8 0.7 0.0029 Bacalar C. 27 14.9 8.6 0.8 0.7 0.0000

Sian Kaan/Ambergri Mex Rocks 27 12.0 7.9 0.0 0.8 0.0000 T. Box 18.5 8.3 6.5 1.8 0.0050 Hol Chan 6.5 11.5 1.6 0.0000

Half Moon 24 39.7 9.2 4.4 1.3 0.0000 Long Caye 12.0 8.5 2.7 2.3 0.0000 Calabash 21 6.9 9.5 1.7 2.1 0.0000 Gallows 30 8.8 7.0 2.0 1.6 0.0000 Goffs 33 22.5 7.4 2.7 1.0 0.0000 Alligator 28 19.7 8.3 2.4 1.6 0.0000 Tobacco 27 5.3 7.3 1.2 1.4 0.0000 S. Water 28 12.5 8.0 4.1 2.5 0.0013 Pelican C. 18 2.6 2.4 0.0 4.4 0.0000 Belize Barrier Reef Gladden 29 9.3 7.4 1.1 0.9 0.0043 Pompion 30 7.0 9.1 1.2 0.8 0.0025 Laughing 24 7.9 6.6 4.0 2.7 0.0057 M. McField, 2002: WWF Mesoamerican Reef Ecoregion Reef Expedition Report 8 Contact: [email protected]

t

s West End 27 26.6 5.4 3.8 2.5 0.0029 Palm View 29 8.7 6.3 8.0 2.0 0.0000 Coa

as Fort Caye 31 9.1 7.3 2.1 0.9 0.0000 Barbareta E 29 10.1 9.9 2.3 0.9 0.0029 dur Garbin Bay 29 5.2 7.6 4.8 1.4 0.0086 Pelican Pt 31 16.2 6.5 6.7 1.9 0.0000 N. Hon Salamandinga 23 4.7 4.6 6.1 1.5 0.0000 C. Redondo 27 5.8 9.7 2.7 3.2 0.0057 C. Paloma 22 4.5 5.2 3.7 1.6 0.0000

Table 2. Results Averaged by Sub-region

Table 2. Overall Data Summary" WWF 2001 Mesoamerica Reef Survey - by Subregion

coral coral Juvenile coral recent diadema richness cover density disease mortality density % dead # species % cover # /m2 % infected tissue m2 N. Q. Roo 24.5 24.5 12.2 3.0 2.7 0.0029 SianK Ambergris 26.4 20.3 7.0 3.7 1.1 0.0008 Belize BR 26.5 12.9 7.6 2.3 1.9 0.0016 N Honduras 27.6 10.1 6.9 4.4 1.8 0.0022 Overall 26.7 15.2 7.5 3.4 1.6 0.0015

Benthic Cover Overall, the reefs had a mean live coral cover of 15.2%, ranging from 2.6% to 39.7%, although sample sizes and methodology varied due to failure of the video cameras. The Northern Quintana Roo sub-region (two sites in Cozumel) had the highest coral cover (24.5%), although this was from only two sites off Cozumel. The twelve sites in the Sian- Ka’an/Ambergris sub-region had a live coral cover of 20.3%. The twelve sites in the Belize Barrier Reef sub-region had a mean coral cover of 12.9%. The nine sites in the Northern Honduras Coast sub-region had a mean coral cover of 10.1%

Coral Species Richness The average number of stony coral species at each site was 26.7, with a range of 18-33 species. The Northern Quintana Roo sub-region had the lowest coral species richness (24.5 species per site) in the ecoregion. The average number of coral species was 26.4 per site in the the Sian-Ka’an/Ambergris sub-region. In Belize Barrier Reef sub-region the average number of coral species was 26.5 species per site. Northern Honduras Coast sub- region had the highest average number of coral species per site ( 27.6).

Recruit Density The average density of recruits/juvenile corals was 7.5/m2, ranging from 1.0 to 14.6/m2.

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The Northern Quintana Roo sub-region (two sites in Cozumel) also had the highest density of recruits / juvenile corals (12.2/m2 ). Sian-Ka’an/Ambergris sub-region had and density of recruits / juvenile corals of 7.0 /m2. The density of recruits / juvenile corals in Belize Barrier Reef sub-region was 7.6/m2. Northern Honduras Coast sub-region had a density of recruits / juvenile corals of 6.9/m2.

Coral Disease and Mortality Approximately 3.3 % of the 3,692 corals surveyed had active disease infections, ranging from 0-11.5%. White plague and dark spot diseases were the most common types in the ecoregion, although this varied by sub-region. Dark spot and white band were more common in the northern two sub-regions while black band and white plague were more common in the southern sub-regions. As more is learned about the precise agents and conditions promoting these diseases, these data maybe able to help pinpoint specific impacts in these zones. Overall the mean percent of recent mortality (indicating the percent of each colony that is thought to have died in the last year) in the ecoregion was 1.7%, with a range of 0.2 to 4.4%. The mean disease infection rate in the Northern Quintana Roo sub-region was 3.0%, with dark spot being the most common disease Corals in this sub-region had the highest recent mortality (2.7%). The Sian- Ka’an/Ambergris sub-region had a mean disease infection rate was 3.7%, with dark spot being the most common disease. Corals in this sub-region had the lowest percent of recent mortality (1.1%). There was high variability between sites in this sub-region, particularly regarding disease rates and coral cover .The mean disease infection rate in the Belize Barrier Reef sub-region was 2.3%, with white plague being the most common disease. Corals in this sub-region had an average recent mortality of 1.9%. Northern Honduras Coast sub-region had mean disease infection rate of 4.4%, with white plague being the most common disease. Corals in this sub-region had recent mortality of 1.8%.

Table 3 GPS Coordinates of sites

MACR Reef Survey Site Coordinates:

# Name N W 1 Contoy 21 27.960 086 46.892 2 P. "Bajo" 20 28.220 086 58.940 3 Palancar 20 19.863 087 01.645 4 P.Paila 20 02.007 087 27.888 5 P. Yuyum 19 58.553 087 27.031 6 Mosquitero 19 13.799 087 30.486 7 Mahahual 18 42.644 087 42.172 8 Coordillara 18 32.481 087 25.520 9 Far Star 18 23.568 087 21.462 10 Jomna 18 22.889 087 46.540 11 Canones 18 16.681 087 49.223 12 Bacalar Chico 18 09.769 087 49.333 13 Mexico Rocks 17 59.174 087 54.233 14 Tackle Box 17 54.677 087 57.079

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15 Hol Chan 17 51.780 087 58.360 16 Gallows 17 29.706 088 02.550 17 Goffs 17 21.115 088 01.730 18 Calabash 17 15.659 087 49.128 19 Long Caye 17 13.515 087 36.286 20 Half Moon 17 12.300 087 32.798 21 Alligator 17 11.832 088 03.129 22 Tobacco 16 55.117 088 02.828 23 S. Water 16 48.814 088 04.641 24 Pelican C. 16 41.057 088 11.217 25 Gladden 16 31 087 58 26 Laughing 16 26.203 088 11.941 27 Pompion 16 22.388 088 05.350 28 Garbin Bay 16 27.103 086 09.060 29 Barbareta E 16 24.484 086 08.422 30 Fort Caye 16 23.933 086 16.944 31 West End 16 17.851 086 36.018 32 Palm View 33 Pelican Pt 15 58.550 086 29.261 34 C. Redondo 15 57.298 086 28.184 35 C. Paloma 15 56.541 086 30.100 36 Salamandinga 15 55.503 086 33.077

Literature Cited

Aronson R.B and D.W. Swanson. 1997. Video surveys of coral reefs: uni- and multivariate applications. Proceedings of the 8th International Coral Reef Symposium. 2:1441-1446.

Kramer, P.A. and P.R. Kramer. 2000. Ecological Status of the Mesoamerican Barrier Reef: impacts of Hurricane Mitch and 1998 coral bleaching. Final report to the World Bank.

McField, M.D. (1999). Coral response during and after mass bleaching in Belize. Bull. Mar. Sci. 64(1): 155-172.

McField, M.D., P. Hallock and W. Jaap. 2001. Multivariate Analysis of Reef Community Structure in the Belize Barrier Reef Complex. Bull. Mar. Sci. 69(2):745-758.

Wheaton, J. W. Jaap, P. Dustan, and J. Porter. 1996. Florida Keys National Marine Sanctuary, Coral Reef and Hardbottom Monitoring Project. Annual Report to EPA. FO438-94-18/A2.

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