DOCSLIB.ORG

Effects of Wave Exposure on Intertidal Fucoid Algae

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Effects of Wave Exposure on Intertidal Fucoid Algae EFFECTS OF WAVE EXPOSURE ON INTERTIDAL FUCOID ALGAE Carol Anne Blanchette1, Carol Thornber2, and Steven D. Gaines3 1Marine Science Institute and Department of Ecology, Evolution and Marine Biology University of California, Santa Barbara, CA 93106 (805) 893-7295, FAX (805) 893-8062, E-mail: [email protected] 2Department of Ecology, Evolution and Marine Biology University of California, Santa Barbara, CA 93106 (805) 893-7397, FAX (805) 893-8062, E-mail: [email protected] 3Marine Science Institute and Department of Ecology, Evolution and Marine Biology University of California, Santa Barbara, CA 93106 (805) 893-7379, FAX (805) 893-8062, E-mail: [email protected] ABSTRACT Two species of intertidal fucoid algae, Pelvetia distributions both extend across broad geographic areas from compressa and Hesperophycus californicus, are commonly northern California (and British Columbia for Pelvetia) to found along moderately wave exposed rocky intertidal re- Baja, yet are distributed patchily within these broad areas. gions along the California coast. Both species decrease in Some of the factors known to influence the local distribu- size and abundance going from wave-protected to wave- tions of intertidal species include wave action, nutrient/food exposed intertidal areas. On the west end of Santa Cruz Is- availability, rock type, and intensity of grazing/predation and land there is a noticeable gradient in wave exposure from competition. It is likely that some or all of these environ- Forney Cove to Frasier Point. In order to evaluate the ef- mental factors may influence distributions depending on the fects of both wave exposure and tidal height on size and particular location, however in this study we focus our at- survival of these two species, we transplanted 20 adults and tention on the effects of wave exposure. juveniles of both species from a wave-protected site (Forney) Exposure to wave action is generally considered an to an adjacent wave-exposed site (Frasier) at both high and important factor in the distribution and abundance of inter- low tidal heights, as well as 20 individuals of each species tidal organisms (Carefoot 1977; Denny 1988; Vadas et al. and age from Forney to Forney to control for transplant ef- 1990). In shallow marine and intertidal areas, a dramatic fects. Survival of adult Pelvetia was highest in the low zone environmental gradient exists among shores exposed to dif- at Frasier and low at both Forney and Frasier high. Survival ferent levels of wave action. Wave action and water move- of Pelvetia juveniles was extremely low at both tidal heights ment are known to influence species size, morphology, and at Frasier. Hesperophycus survival at Frasier did not differ distribution patterns, and organisms on wave-swept shores from that at Forney for either adults or juveniles. The most are often much smaller than those in more wave-protected dramatic effect of transplantation was on plant size. All in- habitats (Lewis 1968; Menge 1976; Blanchette 1997). These dividuals transplanted to Frasier were immediately reduced trends occur both within species, and between sites of close in size relative to controls. These results are consistent with proximity. Examples include mussels and seastars (Harger the idea that wave action can prevent plants from attaining 1970, 1972; Paine 1976 a,b), gastropods (Kitching et al. large sizes in wave-swept intertidal areas. 1966; Behrens 1972; Etter 1989; Boulding 1990; Boulding and Van Alstyne 1993), and seaweeds (Russell 1978; Keywords: Pelvetia compressa, Hesperophycus Schonbeck and Norton 1981; Norton 1991). Organisms liv- californicus, Santa Cruz Island, Frasier Point, Forney Cove, ing in wave-swept intertidal environments are subjected to wave exposure, algal size. some of the highest hydrodynamic forces on earth which scale with both the magnitude of the flow and the size of the INTRODUCTION organism (Denny et al. 1985, 1988). Dislodgment or break- age can occur when the force exceeds the strength of the Both ecologists and biogeographers have been long organism or its attachment to the rock. Thus, survival in this interested in determining the factors limiting the distribu- environment is enhanced by features which minimize the tions of species in nature. Although particular species may forces that an organism experiences, and therefore minimizes have distributions which extend across broad geographical its risk of being broken or torn from the rock. These features areas, they may be locally rare within their geographical may include high attachment strength, high breaking strength, range. This pattern holds for two marine algal species, high flexibility and extensibility, small size, low drag mor- Hesperophycus californicus and Pelvetia compressa, whose phology, and/or a combination of these traits (Koehl 1977, 347 Blanchette, C. A., et al. 1982; Denny et al. 1985; Holbrook et al. 1991; Gaylord et • How does wave exposure influence size and al. 1994; and Dudgeon and Johnson 1992). Most marine survival in both Pelvetia and Hesperophycus? plants do not have a fixed morphology throughout their life- time, and are able to modify their shape and size to suit con- • Do these effects depend on plant age? ditions. Sub-lethal forces may break off several branches of a plant reducing its overall size. In this case, the plant’s prob- • To what degree do the size and survival of ability of survival is increased, since the size of the plant is wave exposed transplants depend on tidal height? reduced while its tenacity remains unaffected. This pattern of thallus breakage was documented in a field experiment in METHODS which the intertidal rockweed, Fucus gardneri, was recip- rocally transplanted between wave-exposed and wave-pro- Study Location tected sites (Blanchette 1997). Large plants from the wave- This study was carried out at Frasier Point, on the protected site were not immediately dislodged by wave ac- western end of Santa Cruz Island. The point is a rocky (ba- tion at the exposed site. They were, however, reduced in salt) headland fully exposed to oceanic waves on the north- size over time as branches were pruned by wave action. western side (hereafter referred to as ‘Frasier’), and the south- The west end of Santa Cruz Island provides an ideal western side (hereafter referred to as ‘Forney’) is protected setting to examine the effects of wave exposure on intertidal from swells (Figure 1). Experimental plots were located on organisms. Frasier Point is directly exposed to the prevail- horizontal rock surfaces in the mid-intertidal zone and ranged ing swells from the northwest and is extremely wave ex- from 2.2 to 3.0 m above mean lower low water (MLLW). posed (Figure 1). Forney Cove lies on the opposite side of The high-zone, wave-exposed community at Frasier was this peninsula to the south and is very much protected from dominated by Porphyra perforata, Endocladia muricata, wave action (Apt et al. 1988; Tissot 1995). Swells from the and the barnacles Balanus glandula and Chthamalus fissus. south are more rare, and much of the wave intensity gener- The most abundant herbivores were the limpets Lottia digi- ated by a south swell is broken up by a large rocky point and talis, L. pelta, L. strigatella and the snail Littorina scutulata. therefore does not reach the intertidal area. Both The high-zone, wave-protected community at Forney was Hesperophycus and Pelvetia are extremely abundant at dominated by Pelvetia compressa and Hesperophycus Forney, yet are absent or extremely rare at Frasier (Apt et al. californicus. The barnacles B. glandula and C. fissus were 1988). The few plants at Frasier appear extremely small and patchily present at this site and the snails Littorina scutulata “stunted” relative to the Forney population, suggesting that and Tegula funebralis were the most abundant grazers. wave exposure may also be a limiting factor in their ability to grow to a large size (authors’ pers. obs.). Study Organisms In order to examine the effects of wave exposure on Pelvetia compressa and Hesperophycus californicus the size and survival of both Hesperophycus and Pelvetia, are both common high intertidal fucoid brown algae. The we transplanted both species to Frasier as well as back to thallus of Hesperophycus californicus is attached by a broad Forney to control for the transplant procedure. Our study discoid holdfast, from which arise bilaterally branched flat- attempts to address the following questions: tened fronds with a distinct midrib. Receptacles are present Figure 1. Western point of Santa Cruz Island. Frasier is the more wave exposed site to the north (right) and Forney is the protected cove to the south (left). 348 Effects of Waves on Fucoid Algae at the apices of mature plants and become swollen at the by photographing each individual against a white sheet next time of reproduction. Fertile plants are found in the popula- to a ruler and analyzing plant area using an image process- tion throughout the year. Plant growth is apical and branch- ing program (Image 1.41, National Institute of Health). Since ing is dichotomous. Reproductive structures (conceptacles) both Hesperophycus and Pelvetia can perennate and regrow develop from cells in receptacles of higher order branches. from a holdfast, plants were recorded as missing only when The modular character of Hesperophycus means that a single the entire holdfast was dislodged. plant may be reproductive throughout the year as branches reach reproductive maturity at different times. Data Analysis Hesperophycus
Load more

Recommended publications
  • Pelvetia Canaliculata Channel Wrack Ecology and Similar Identification Species
    Ecology and Similar species identification Found slightly High shore alga higher than often forming a Fucus spiralis. clear zone on Fronds in more sheltered F.spiralis are shores. flat and twisted. Evenly forked fronds up to 15cm long that are rolled to give a channel on one side. Pelvetia canaliculata Channel Wrack Ecology and Similar identification species High shore alga Fucus often forming vesiculosus a clear zone which has below Pelvetia distinctive air on more bladders sheltered shores. Fronds in F.spiralis are flat and Fucus spiralis twisted and up Spiral Wrack to 20cm long. NO air bladders. Ecology and Similar identification species Most Fucus characteristic vesiculosus mid shore which has alga in shelter. paired circular air Leathery bladders fronds up to a metre long, no mid-rib and single egg-shaped Ascophyllum nodosum air-bladders Egg or Knotted Wrack Ecology and Similar identification species The F. spiralis characteristic and alga of the A.nodosum mid-shore in moderate exposure. The fronds have a prominent mid-rib and Fucus vesiculosus paired air Bladder Wrack bladders. Ecology and Similar identification species Can be Other Fucus abundant in species the low and lower mid- shore. Fronds have a serrated edge. Fucus serratus Serrated Wrack. Ecology and Similar species identification. This is the Laminaria commonest of hyperborea, the the kelps and can forest kelp, dominate around which has a low water. Each round cross plant may reach section to the 1.5m long. stem and stands erect at The stem has an low tide. oval cross section that causes the plant to droop over at low water.
    [Show full text]
  • Fucus Vesiculosus Populations?
    l MARINE ECOLOGY PROGRESS SERIES Vol. 133: 191-201.1996 Published March 28 1 Mar Ecol Prog Ser Are neighbours harmful or helpful in Fucus vesiculosus populations? Joel C. Creed*,T. A. Norton, Joanna M. Kain (Jones) Port Erin Marine Laboratory, Port Erin. Isle of Man IM9 6JA, United Kingdom ABSTRACT: In order to investigate the effect of density on Fucus vesjculosus L. at all stages of its development, 2 experiments were carried out. A culture study in the laboratory found that increased density resulted in depressed growth and a negatively skewed population structure during the first month in the lives of freshly settled germlings. Intraspecific competition acts even at this early stage, and the limiting factor was probably nutrients. 'Two-sided' ('resource depletion') competition and an early scramble phase of growth may explain negative skewness in plant sizes. On the shore experi- mental thinning by reduction of the canopy resulted in increased macrorecruitment (apparent density) from a bank of microscopic plants which must have been present for some time. With increased thinning more macrorecruits loined the remaining plants, making population size structures highly posit~velyskewed. Thinning had no effect on reproduction In terms of the portion of biomass as repro- ductive tissue. Manipulative weedlng allows an assessment of the potent~alspore bank in seasonally reproductive seaweeds and revealed that there are always replacement plants in reserve to compen- sate for canopy losses. In E vesiculosus the performance of individuals early on is crucial to their sub- sequent survival to reproductive stage, as neighbours are generally competitively harmful. However, a failure to 'win' early on may not necessarily result in the ending of a small plant's life - the 'seed' bank still offers the individual a slim chance of survival and protects the population from harmful stochastic events KEY WORDS: Culture .
    [Show full text]
  • Processing of Allochthonous Macrophyte Subsidies by Sandy Beach Consumers: Estimates of Feeding Rates and Impacts on Food Resources
    Mar Biol DOI 10.1007/s00227-008-0913-3 RESEARCH ARTICLE Processing of allochthonous macrophyte subsidies by sandy beach consumers: estimates of feeding rates and impacts on food resources Mariano Lastra · Henry M. Page · Jenifer E. Dugan · David M. Hubbard · Ivan F. Rodil Received: 29 January 2007 / Accepted: 8 January 2008 © Springer-Verlag 2008 Abstract Allochthonous subsidies of organic material impact on drift macrophyte processing and fate and that the can profoundly inXuence population and community struc- quantity and composition of drift macrophytes could, in ture; however, the role of consumers in the processing of turn, limit populations of beach consumers. these inputs is less understood but may be closely linked to community and ecosystem function. Inputs of drift macro- phytes subsidize sandy beach communities and food webs Introduction in many regions. We estimated feeding rates of dominant sandy beach consumers, the talitrid amphipods (Megalor- Allochthonous inputs of organic matter can strongly inXu- chestia corniculata, in southern California, USA, and Tali- ence population and community structure in many eco- trus saltator, in southern Galicia, Spain), and their impacts systems (e.g., Polis and Hurd 1996; Cross et al. 2006). on drift macrophyte subsidies in Weld and laboratory exper- Such eVects are expected to be greatest where a highly iments. Feeding rate varied with macrophyte type and, for productive system interfaces with and exports materials to T. saltator, air temperature. Size-speciWc feeding rates of a relatively less productive system (Barrett et al. 2005). talitrid amphipods were greatest on brown macroalgae Ecosystems that are subsidized by allochthonous inputs (Macrocystis, Egregia, Saccorhiza and Fucus).
    [Show full text]
  • Getative Tissues; the GDBH Predicts Metabolic Costs Associated with Them
    J. Phycol. 35, 483±492 (1999) PHLOROTANNIN ALLOCATION AMONG TISSUES OF NORTHEASTERN PACIFIC KELPS AND ROCKWEEDS1 Kathryn L. Van Alstyne2 Department of Zoology, Oregon State University, Corvallis, Oregon 97331 James J. McCarthy III, Cynthia L. Hustead, and Laura J. Kearns Department of Biology, Kenyon College, Gambier, Ohio 43022 Optimal defense theory (ODT) predicts antiher- Abbreviations: DM, dry mass; GDBH, growth±dif- bivore defensive compounds will be allocated so ferentiation balance hypothesis; ODT, optimal de- that the most valuable or most susceptible tissues fense theory will be best defended. The growth±differentiation balance hypothesis (GDBH) predicts that defense al- location will be a result of trade-offs between growth Plants allocate materials and energy among criti- and defense. Thus, these two theories predict op- cal functions such as maintenance, growth, repro- posite allocation patterns with respect to ``valuable,'' duction, and defense (Bazazz and Grace 1997 and actively growing meristematic and reproductive tis- citations therein). It is widely assumed the total sues. ODT predicts that meristems and reproductive amount of resources available for these functions is tissues should have higher defense levels than non- limited and all of these functions have signi®cant meristematic vegetative tissues; the GDBH predicts metabolic costs associated with them. Consequently, the defense levels of meristems and reproductive over evolutionary time there should be selection for tissues will be lower than vegetative tissues. We ex- individuals to distribute resources among functions amined allocation patterns of phlorotannins in 21 in ways that maximize overall ®tness, assuming that species of kelps (Order Laminariales) and rock- allocation strategies are not limited by physiological weeds (Order Fucales) from nine sites on the west or other constraints.
    [Show full text]
  • Plants and Ecology 2013:2
    Fucus radicans – Reproduction, adaptation & distribution patterns by Ellen Schagerström Plants & Ecology The Department of Ecology, 2013/2 Environment and Plant Sciences Stockholm University Fucus radicans - Reproduction, adaptation & distribution patterns by Ellen Schagerström Supervisors: Lena Kautsky & Sofia Wikström Plants & Ecology The Department of Ecology, 2013/2 Environment and Plant Sciences Stockholm University Plants & Ecology The Department of Ecology, Environment and Plant Sciences Stockholm University S-106 91 Stockholm Sweden © The Department of Ecology, Environment and Plant Sciences ISSN 1651-9248 Printed by FMV Printcenter Cover: Fucus radicans and Fucus vesiculosus together in a tank. Photo by Ellen Schagerström Summary The Baltic Sea is considered an ecological marginal environment, where both marine and freshwater species struggle to adapt to its ever changing conditions. Fucus vesiculosus (bladderwrack) is commonly seen as the foundation species in the Baltic Sea, as it is the only large perennial macroalgae, forming vast belts down to a depth of about 10 meters. The salinity gradient results in an increasing salinity stress for all marine organisms. This is commonly seen in many species as a reduction in size. What was previously described as a low salinity induced dwarf morph of F. vesiculosus was recently proved to be a separate species, when genetic tools were used. This new species, Fucus radicans (narrow wrack) might be the first endemic species to the Baltic Sea, having separated from its mother species F. vesiculosus as recent as 400 years ago. Fucus radicans is only found in the Bothnian Sea and around the Estonian island Saaremaa. The Swedish/Finnish populations have a surprisingly high level of clonality.
    [Show full text]
  • Marlin Marine Information Network Information on the Species and Habitats Around the Coasts and Sea of the British Isles
    MarLIN Marine Information Network Information on the species and habitats around the coasts and sea of the British Isles Spiral wrack (Fucus spiralis) MarLIN – Marine Life Information Network Biology and Sensitivity Key Information Review Nicola White 2008-05-29 A report from: The Marine Life Information Network, Marine Biological Association of the United Kingdom. Please note. This MarESA report is a dated version of the online review. Please refer to the website for the most up-to-date version [https://www.marlin.ac.uk/species/detail/1337]. All terms and the MarESA methodology are outlined on the website (https://www.marlin.ac.uk) This review can be cited as: White, N. 2008. Fucus spiralis Spiral wrack. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. DOI https://dx.doi.org/10.17031/marlinsp.1337.1 The information (TEXT ONLY) provided by the Marine Life Information Network (MarLIN) is licensed under a Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales License. Note that images and other media featured on this page are each governed by their own terms and conditions and they may or may not be available for reuse. Permissions beyond the scope of this license are available here. Based on a work at www.marlin.ac.uk (page left blank) Date: 2008-05-29 Spiral wrack (Fucus spiralis) - Marine Life Information Network See online review for distribution map Detail of Fucus spiralis fronds. Distribution data supplied by the Ocean Photographer: Keith Hiscock Biogeographic Information System (OBIS).
    [Show full text]
  • Marlin Marine Information Network Information on the Species and Habitats Around the Coasts and Sea of the British Isles
    MarLIN Marine Information Network Information on the species and habitats around the coasts and sea of the British Isles Channelled wrack (Pelvetia canaliculata) MarLIN – Marine Life Information Network Biology and Sensitivity Key Information Review Nicola White 2008-05-29 A report from: The Marine Life Information Network, Marine Biological Association of the United Kingdom. Please note. This MarESA report is a dated version of the online review. Please refer to the website for the most up-to-date version [https://www.marlin.ac.uk/species/detail/1342]. All terms and the MarESA methodology are outlined on the website (https://www.marlin.ac.uk) This review can be cited as: White, N. 2008. Pelvetia canaliculata Channelled wrack. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. DOI https://dx.doi.org/10.17031/marlinsp.1342.1 The information (TEXT ONLY) provided by the Marine Life Information Network (MarLIN) is licensed under a Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales License. Note that images and other media featured on this page are each governed by their own terms and conditions and they may or may not be available for reuse. Permissions beyond the scope of this license are available here. Based on a work at www.marlin.ac.uk (page left blank) Date: 2008-05-29 Channelled wrack (Pelvetia canaliculata) - Marine Life Information Network See online review for distribution map Pelvetia canaliculata at the water's edge. Distribution data supplied by the Ocean Photographer: Judith Oakley Biogeographic Information System (OBIS).
    [Show full text]
  • Cryptic Diversity, Geographical Endemism and Allopolyploidy in NE Pacific Seaweeds
    UC Santa Cruz UC Santa Cruz Previously Published Works Title Cryptic diversity, geographical endemism and allopolyploidy in NE Pacific seaweeds. Permalink https://escholarship.org/uc/item/2h1803cx Journal BMC evolutionary biology, 17(1) ISSN 1471-2148 Authors Neiva, João Serrão, Ester A Anderson, Laura et al. Publication Date 2017-01-23 DOI 10.1186/s12862-017-0878-2 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Neiva et al. BMC Evolutionary Biology (2017) 17:30 DOI 10.1186/s12862-017-0878-2 RESEARCH ARTICLE Open Access Cryptic diversity, geographical endemism and allopolyploidy in NE Pacific seaweeds João Neiva1*† , Ester A. Serrão1†, Laura Anderson2, Peter T. Raimondi2, Neusa Martins1, Licínia Gouveia1, Cristina Paulino1, Nelson C. Coelho1, Kathy Ann Miller3, Daniel C. Reed4, Lydia B. Ladah5 and Gareth A. Pearson1 Abstract Background: Molecular markers are revealing a much more diverse and evolutionarily complex picture of marine biodiversity than previously anticipated. Cryptic and/or endemic marine species are continually being found throughout the world oceans, predominantly in inconspicuous tropical groups but also in larger, canopy-forming taxa from well studied temperate regions. Interspecific hybridization has also been found to be prevalent in many marine groups, for instance within dense congeneric assemblages, with introgressive gene-flow being the most common outcome. Here, using a congeneric phylogeographic approach, we investigated two monotypic and geographically complementary sister genera of north-east Pacific intertidal seaweeds (Hesperophycus and Pelvetiopsis), for which preliminary molecular tests revealed unexpected conflicts consistent with unrecognized cryptic diversity and hybridization. Results: The three recovered mtDNA clades did not match a priori species delimitations.
    [Show full text]
  • Fucoid Algae As Model Organisms for Investigating Early Embryogenesis
    Cah. Biol. Mar. (2001) 42 : 101-107 Fucoid algae as model organisms for investigating early embryogenesis Francois-Yves BOUGET1, Florence CORELLOU1 & Darryl L. KROPF2* 1 UMR 1931 CNRS-Goëmar, Station Biologique CNRS-INSU-Université Paris 6, Place Georges-Teissier, BP 74, F29682 Roscoff Cedex, France. 2 University of Utah, Department of Biology, 257 South 1400 East Salt Lake City, UT 84112-0840, USA E-mail: [email protected] * Author for correspondence Abstract: In the past few years, there have been exciting advances in our understanding of the mechanisms that control morphogenesis in fucoid embryos. In this article we review recent findings from our laboratories concerning 1) polarity establishment and expression in the zygote and 2) development of the zygote into a multicellular embryo. Résumé : Durant la dernière décennie, des avancées importantes ont été réalisées dans la compréhension des mécanismes qui contrôlent la morphogenèse des embryons de Fucacées. Dans cette revue, nous présentons les résultats récents obtenus dans nos laboratoires respectifs concernant 1) l’établissement de la polarité et son expression dans le zygote et 2) le déve- loppement du zygote en un embryon pluricellulaire. Keywords : Fucus, Pelvetia, embryogenesis, polarity. Introduction onto the substratum (rocks in the intertidal zone) where they attach tenaciously by a secreted adhesive (Vreeland et al., In addition to their importance as sources of natural 1993). Rapid adhesion is critical for survival because polymers and foods, many marine algae also provide zygotes that fail to attach are washed out to sea in the next excellent opportunities for investigating the mechanisms tidal cycle. As was first recognized over 100 years ago by that control development.
    [Show full text]
  • Ascophyllum Nodosum) in Breiðafjörður, Iceland: Effects of Environmental Factors on Biomass and Plant Height
    Rockweed (Ascophyllum nodosum) in Breiðafjörður, Iceland: Effects of environmental factors on biomass and plant height Lilja Gunnarsdóttir Faculty of Life and Environmental Sciences University of Iceland 2017 Rockweed (Ascophyllum nodosum) in Breiðafjörður, Iceland: Effects of environmental factors on biomass and plant height Lilja Gunnarsdóttir 60 ECTS thesis submitted in partial fulfillment of a Magister Scientiarum degree in Environment and Natural Resources MS Committee Mariana Lucia Tamayo Karl Gunnarsson Master’s Examiner Jörundur Svavarsson Faculty of Life and Environmental Science School of Engineering and Natural Sciences University of Iceland Reykjavik, December 2017 Rockweed (Ascophyllum nodosum) in Breiðafjörður, Iceland: Effects of environmental factors on biomass and plant height Rockweed in Breiðafjörður, Iceland 60 ECTS thesis submitted in partial fulfillment of a Magister Scientiarum degree in Environment and Natural Resources Copyright © 2017 Lilja Gunnarsdóttir All rights reserved Faculty of Life and Environmental Science School of Engineering and Natural Sciences University of Iceland Askja, Sturlugata 7 101, Reykjavik Iceland Telephone: 525 4000 Bibliographic information: Lilja Gunnarsdóttir, 2017, Rockweed (Ascophyllum nodosum) in Breiðafjörður, Iceland: Effects of environmental factors on biomass and plant height, Master’s thesis, Faculty of Life and Environmental Science, University of Iceland, pp. 48 Printing: Háskólaprent Reykjavik, Iceland, December 2017 Abstract During the Last Glacial Maximum (LGM) ice covered all rocky shores in eastern N-America while on the shores of Europe ice reached south of Ireland where rocky shores were found south of the glacier. After the LGM, rocky shores ecosystem development along European coasts was influenced mainly by movement of the littoral species in the wake of receding ice, while rocky shores of Iceland and NE-America were most likely colonized from N- Europe.
    [Show full text]
  • Seaweed Seaweeds Are an Important Food and Medicine to Humans Everywhere That They Grow
    Seaweed Seaweeds are an important food and medicine to humans everywhere that they grow. They have been harvested by Salish People off the Pacific coast for countless generations and are used for thickening soups, seasoning foods, and for baking foods in cooking pits. Seaweeds are exceptionally high in minerals, trace elements and protein. They can be preserved through careful drying in the sun or near a fire. Where they grow: In salt water at middle to low tidal zones. Each type of seaweed has a tidal zone habitat – from sea lettuce and bladder wrack that grow on rocks in upper tidal zones to bull whip kelp, which grows in deep waters. Season: Like other edible plant greens, seaweeds are harvested in spring and early summer when they are most vital. In late summer and fall they get tougher and begin to deteriorate. How to Harvest: It is very important to harvest seaweeds from clean waters because they can absorb environmental toxins. The safest places are open waters of the Pacific with strong current flow away from cities, towns or industrial runoff. Washington State allows us to harvest 10 pounds wet weight per day on public beaches and you need a shellfish/seaweed license to harvest. The bottom of the seaweed or “hold-fast” anchors on to rocks while leaves grow upward toward the light like an undersea forest. Make sure you leave the holdfast and at least a quarter of the seaweed plant so it can grow back. Do not clear-cut any area so that the seaweed can continue to thrive.
    [Show full text]
  • Adaptive Phenotypic Differentiation Across the Intertidal Gradient in the Alga Silvetia Compressa
    Ecology, 88(1), 2007, pp. 149–157 Ó 2007 by the Ecological Society of America ADAPTIVE PHENOTYPIC DIFFERENTIATION ACROSS THE INTERTIDAL GRADIENT IN THE ALGA SILVETIA COMPRESSA 1 CYNTHIA G. HAYS Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California 95060 USA Abstract. Populations of intertidal species span a steep environmental gradient driven by differences in emersion time. In spite of strong differential selection on traits related to this gradient, the small spatial scale over which differences occur may prevent local adaptation, and instead may favor a single intermediate phenotype, or nongenetic mechanisms of differentiation. Here I examine whether a common macroalga, Silvetia compressa, exhibits phenotypic differentiation across the intertidal gradient and evaluate how local adaptation, developmental plasticity, and maternal effects may interact to shape individual phenotypes. Reciprocal transplants of both adults and embryos showed a ‘‘home-height advantage’’ in two of the three populations tested. In laboratory trials, the progeny of upper-limit individuals survived exposure to air significantly better than lower-limit progeny from the same population. I compared the emersion tolerance of full-sib families generated from gametes produced in the field to those produced under common garden conditions. The relative advantage of upper-limit lineages was robust to maternal environment during gametogenesis; this pattern is consistent with genetic differentiation. The possible role of local adaptation has historically been ignored in studies of intertidal zonation. In S. compressa, phenotypic differentiation may have important consequences for vertical range, both within and among sites. Key words: algae; environmental gradient; intertidal; local adaptation; maternal effect; phenotypic plasticity; Silvetia compressa.
    [Show full text]