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Meira A, Byers JE, Sousa R. A global synthesis of predation on bivalves. Biol Rev Camb Philos Soc 2024; 99:1015-1057. [PMID: 38294132 DOI: 10.1111/brv.13057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/29/2023] [Accepted: 01/16/2024] [Indexed: 02/01/2024]
Abstract
Predation is a dominant structuring force in ecological communities. In aquatic environments, predation on bivalves has long been an important focal interaction for ecological study because bivalves have central roles as ecosystem engineers, basal components of food webs, and commercial commodities. Studies of bivalves are common, not only because of bivalves' central roles, but also due to the relative ease of studying predatory effects on this taxonomic group. To understand patterns in the interactions of bivalves and their predators we synthesised data from 52 years of peer-reviewed studies on bivalve predation. Using a systematic search, we compiled 1334 studies from 75 countries, comprising 61 bivalve families (N = 2259), dominated by Mytilidae (29% of bivalves), Veneridae (14%), Ostreidae (8%), Unionidae (7%), and Dreissenidae and Tellinidae (6% each). A total of 2036 predators were studied, with crustaceans the most studied predator group (34% of predators), followed by fishes (24%), molluscs (17%), echinoderms (10%) and birds (6%). The majority of studies (86%) were conducted in marine systems, in part driven by the high commercial value of marine bivalves. Studies in freshwater ecosystems were dominated by non-native bivalves and non-native predator species, which probably reflects the important role of biological invasions affecting freshwater biodiversity. In fact, while 81% of the studied marine bivalve species were native, only 50% of the freshwater species were native to the system. In terms of approach, most studies used predation trials, visual analysis of digested contents and exclusion experiments to assess the effects of predation. These studies reflect that many factors influence bivalve predation depending on the species studied, including (i) species traits (e.g. behaviour, morphology, defence mechanisms), (ii) other biotic interactions (e.g. presence of competitors, parasites or diseases), and (iii) environmental context (e.g. temperature, current velocity, beach exposure, habitat complexity). There is a lack of research on the effects of bivalve predation at the population and community and ecosystem levels (only 7% and 0.5% of studies respectively examined impacts at these levels). At the population level, the available studies demonstrate that predation can decrease bivalve density through consumption or the reduction of recruitment. At the community and ecosystem level, predation can trigger effects that cascade through trophic levels or effects that alter the ecological functions bivalves perform. Given the conservation and commercial importance of many bivalve species, studies of predation should be pursued in the context of global change, particularly climate change, acidification and biological invasions.
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Affiliation(s)
- Alexandra Meira
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus Gualtar, Braga, 4710-057, Portugal
| | - James E Byers
- Odum School of Ecology, University of Georgia, 140 E. Green St, Athens, GA, 30602, USA
| | - Ronaldo Sousa
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus Gualtar, Braga, 4710-057, Portugal
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Hanley TC, Grabowski JH, Schneider EG, Barrett PD, Puishys LM, Spadafore R, McManus G, Helt WSK, Kinney H, Conor McManus M, Randall Hughes A. Host genetic identity determines parasite community structure across time and space in oyster restoration. Proc Biol Sci 2023; 290:20222560. [PMID: 36987644 PMCID: PMC10050946 DOI: 10.1098/rspb.2022.2560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 02/28/2023] [Indexed: 03/30/2023] Open
Abstract
Intraspecific variation in host susceptibility to individual parasite species is common, yet how these effects scale to mediate the structure of diverse parasite communities in nature is less well understood. To address this knowledge gap, we tested how host genetic identity affects parasite communities on restored reefs seeded with juvenile oysters from different sources-a regional commercial hatchery or one of two wild progenitor lines. We assessed prevalence and intensity of three micro- and two macroparasite species for 4 years following restoration. Despite the spatial proximity of restored reefs, oyster source identity strongly predicted parasite community prevalence across all years, with sources varying in their relative susceptibility to different parasites. Oyster seed source also predicted reef-level parasite intensities across space and through time. Our results highlight that host intraspecific variation can shape parasite community structure in natural systems, and reinforce the importance of considering source identity and diversity in restoration design.
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Affiliation(s)
- Torrance C. Hanley
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
- Massachusetts Bays National Estuary Partnership, Boston, MA 02114, USA
| | | | - Eric G. Schneider
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
- Rhode Island Department of Environmental Management, Division of Marine Fisheries, Jamestown, RI 02835, USA
| | - Patrick D. Barrett
- Rhode Island Department of Environmental Management, Division of Marine Fisheries, Jamestown, RI 02835, USA
| | - Lauren M. Puishys
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
| | - Rachele Spadafore
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
| | - Gwendolyn McManus
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
| | | | - Heather Kinney
- The Nature Conservancy, Rhode Island Chapter, Providence, RI 02906, USA
| | - M. Conor McManus
- Rhode Island Department of Environmental Management, Division of Marine Fisheries, Jamestown, RI 02835, USA
| | - A. Randall Hughes
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
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Hays CG, Hanley TC, Hughes AR, Truskey SB, Zerebecki RA, Sotka EE. Local Adaptation in Marine Foundation Species at Microgeographic Scales. THE BIOLOGICAL BULLETIN 2021; 241:16-29. [PMID: 34436968 DOI: 10.1086/714821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
AbstractNearshore foundation species in coastal and estuarine systems (e.g., salt marsh grasses, mangroves, seagrasses, corals) drive the ecological functions of ecosystems and entire biomes by creating physical structure that alters local abiotic conditions and influences species interactions and composition. The resilience of foundation species and the ecosystem functions they provide depends on their phenotypic and genetic responses to spatial and temporal shifts in environmental conditions. In this review, we explore what is known about the causes and consequences of adaptive genetic differentiation in marine foundation species over spatial scales shorter than dispersal capabilities (i.e., microgeographic scales). We describe the strength of coupling field and laboratory experiments with population genetic techniques to illuminate patterns of local adaptation, and we illustrate this approach by using several foundation species. Among the major themes that emerge from our review include (1) adaptive differentiation of marine foundation species repeatedly evolves along vertical (i.e., elevation or depth) gradients, and (2) mating system and phenology may facilitate this differentiation. Microgeographic adaptation is an understudied mechanism potentially underpinning the resilience of many sessile marine species, and this evolutionary mechanism likely has particularly important consequences for the ecosystem functions provided by foundation species.
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Hughes AR, Edwards P, Grabowski JH, Scyphers S, Williams SL. Differential incorporation of scientific advances affects coastal habitat restoration practice. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- A. Randall Hughes
- Marine Science Center Northeastern University Nahant Massachusetts USA
| | - Peter Edwards
- Pew Charitable Trusts Washington District of Columbia USA
- Lynker Technologies Leesburg Virginia USA
| | | | - Steven Scyphers
- Marine Science Center Northeastern University Nahant Massachusetts USA
| | - Susan L. Williams
- Bodega Marine Laboratory University of California Davis Bodega Bay California USA
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5
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Gribben PE, Bishop MJ, O’Connor WA, Bradley DJ, Hughes AR. Intraspecific diversity in prey body size influences survivorship by conferring resistance to predation. Ecosphere 2020. [DOI: 10.1002/ecs2.3106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Paul E. Gribben
- Centre for Marine Science and Innovation School of Earth, Environmental and Biological Sciences University of New South Wales Sydney New South Wales 2052 Australia
- Sydney Institute of Marine Science 19 Chowder Bay Road Mosman New South Wales 2088 Australia
| | - Melanie J. Bishop
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Wayne A. O’Connor
- NSW Department of Primary Industries Nelson Bay New South Wales 2315 Australia
| | - Daniel J. Bradley
- School of Life Sciences University of Technology Sydney New South Wales 2007 Australia
| | - A. Randall Hughes
- Northeastern University Marine Science Centre 430 Nahant Raod Nahant Massachusetts 01908 USA
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Krueger-Hadfield SA, Blakeslee AMH, Fowler AE. Incorporating Ploidy Diversity into Ecological and Community Genetics. JOURNAL OF PHYCOLOGY 2019; 55:1198-1207. [PMID: 31349373 DOI: 10.1111/jpy.12906] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 07/11/2019] [Indexed: 06/10/2023]
Abstract
Studies in ecological and community genetics have advanced our understanding of the role of intraspecific diversity in structuring communities and ecosystems. However, in near-shore marine communities, these studies have mostly been restricted to seagrasses, marsh plants, and oysters. Yet, macroalgae are critically important ecosystem engineers in these communities. Greater intraspecific diversity in a macroalgal ecosystem engineer should result in higher primary and secondary production and community resilience. The paucity of studies investigating the consequences of macroalgal intraspecific genetic variation might be due, in part, to the complexity of macroalgal life cycles. The majority of macroalgae have seemingly subtle, but in actuality, profoundly different life cycles than the more typical animal and angiosperm models. Here, we develop a novel genetic diversity metric, PHD , that incorporates the ratio of gametophytic to sporophytic thalli in natural populations. This metric scales from 0 to 1 like many common genetic diversity metrics, such as genotypic richness, enabling comparisons among metrics. We discuss PHD and examples from the literature, with specific reference to the widespread, red seaweed Agarophyton vermiculophyllum. We also discuss a sex diversity metric, PFM , which also scales from 0 to 1, but fewer studies have identified males and females in natural populations. Nevertheless, by incorporating these novel metrics into the repertoire of diversity metrics, we can explore the role of genetic diversity in community and ecosystem dynamics with an emphasis on the unique biology of many macroalgae, as well as other haplodiplontic taxa such as ferns, foraminiferans, and some fungi.
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Affiliation(s)
- Stacy A Krueger-Hadfield
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd CH464, Birmingham, Alabama, 35294, USA
| | - April M H Blakeslee
- Department of Biology, East Carolina University, E 10th Street, Greenville, North Carolina, 27858, USA
| | - Amy E Fowler
- Department of Environmental Science and Policy, George Mason University, 4400 University Dr, Fairfax, Virginia, 22030, USA
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Hughes AR, Hanley TC, Byers JE, Grabowski JH, McCrudden T, Piehler MF, Kimbro DL. Genetic diversity and phenotypic variation within hatchery-produced oyster cohorts predict size and success in the field. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01940. [PMID: 31148283 DOI: 10.1002/eap.1940] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 04/03/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
The rapid growth of the aquaculture industry to meet global seafood demand offers both risks and opportunities for resource management and conservation. In particular, hatcheries hold promise for stock enhancement and restoration, yet cultivation practices may lead to enhanced variation between populations at the expense of variation within populations, with uncertain implications for performance and resilience. To date, few studies have assessed how production techniques impact genetic diversity and population structure, as well as resultant trait variation in and performance of cultivated offspring. We collaborated with a commercial hatchery to produce multiple cohorts of the eastern oyster (Crassostrea virginica) from field-collected broodstock using standard practices. We recorded key characteristics of the broodstock (male : female ratio, effective population size), quantified the genetic diversity of the resulting cohorts, and tested their trait variation and performance across multiple field sites and experimental conditions. Oyster cohorts produced under the same conditions in a single hatchery varied almost twofold in genetic diversity. In addition, cohort genetic diversity was a significant positive predictor of oyster performance traits, including initial size and survival in the field. Oyster cohorts produced in the hatchery had lower within-cohort genetic variation and higher among-cohort genetic structure than adults surveyed from the same source sites. These findings are consistent with "sweepstakes reproduction" in oysters, even when manually spawned. A readily measured characteristic of broodstock, the ratio of males to females, was positively correlated with within-cohort genetic diversity of the resulting offspring. Thus, this metric may offer a tractable way both to meet short-term production goals for seafood demand and to ensure the capacity of hatchery-produced stock to achieve conservation objectives, such as the recovery of self-sustaining wild populations.
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Affiliation(s)
- A Randall Hughes
- Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908 , USA
| | - Torrance C Hanley
- Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908 , USA
| | - James E Byers
- Odum School of Ecology, University of Georgia, Athens, Georgia, 30602, USA
| | - Jonathan H Grabowski
- Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908 , USA
| | - Tom McCrudden
- Research Aquaculture, Inc., Tequesta, Florida, 33469, USA
| | - Michael F Piehler
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, North Carolina, 28557, USA
| | - David L Kimbro
- Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908 , USA
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Hornick KM, Plough LV. Tracking genetic diversity in a large-scale oyster restoration program: effects of hatchery propagation and initial characterization of diversity on restored vs. wild reefs. Heredity (Edinb) 2019; 123:92-105. [PMID: 30833745 PMCID: PMC6781163 DOI: 10.1038/s41437-019-0202-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/18/2019] [Accepted: 02/11/2019] [Indexed: 01/25/2023] Open
Abstract
The release of hatchery-propagated fish and shellfish is occurring on a global scale, but the genetic impacts of these practices are often not fully understood and rarely monitored. Slow recovery of depleted eastern oyster populations in the Chesapeake Bay, USA has prompted a hatchery-based restoration program focused in the Choptank River, Maryland consisting of the mass release of hatchery-produced juveniles from local, wild broodstock. To evaluate potential genetic effects of this program, we (1) examined changes in genetic diversity (allelic richness, heterozygosity) and the effective number of breeders (Nb) over the hatchery production cycle with microsatellite-based parentage of natural, mass- and controlled-spawned cohorts, and (2) compared genetic diversity and effective population size (Ne) of a restored reef to wild source populations. Mass-spawned cohorts showed high variance in reproductive contribution, particularly among males, leading to a 45% average reduction in Nb from spawning adult numbers and higher relatedness-lower magnitude reductions in heterozygosity and significant reductions in allelic richness were also observed. While controlled-spawns (single-male fertilizations of pooled eggs) reduced male variance, overall reproductive variance (Vk) remained high. Finally, oysters sampled from a restored reef displayed comparable Ne, genetic diversity, and relatedness to samples from wild populations, with no significant genetic differentiation among them. Overall, the hatchery-based results and initial field-based population genetic analyses suggest that despite reductions in diversity from parents to offspring owing to high Vk, enhancement with rotated, wild broodstock appears to have maintained genetic diversity in a restored reef population compared to proximal wild populations.
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Affiliation(s)
- Katherine M Hornick
- University of Maryland Center for Environmental Science, Horn Point Laboratory, 2020 Horns Pt. Rd., Cambridge, MD, 21613, USA.
| | - Louis V Plough
- University of Maryland Center for Environmental Science, Horn Point Laboratory, 2020 Horns Pt. Rd., Cambridge, MD, 21613, USA
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Jaris H, Brown DS, Proestou DA. Assessing the contribution of aquaculture and restoration to wild oyster populations in a Rhode Island coastal lagoon. CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01153-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Short-term low salinity mitigates effects of oil and dispersant on juvenile eastern oysters: A laboratory experiment with implications for oil spill response activities. PLoS One 2018; 13:e0203485. [PMID: 30192837 PMCID: PMC6128549 DOI: 10.1371/journal.pone.0203485] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/21/2018] [Indexed: 01/04/2023] Open
Abstract
Following the Deepwater Horizon oil spill, eastern oyster (Crassostrea virginica) reefs in the northern Gulf of Mexico were exposed to oil and various associated clean-up activities that may have compromised oyster reef health. Included in the exposure was oil, dispersant, and in some locales, atypical salinity regimes. Oil and dispersants can be detrimental to oysters and the effects of salinity depend on the level. In addition to these extrinsic factors, genetic diversity of oyster populations may help the oysters respond to stressors, as demonstrated in other systems. We used a 3×3×2 factorial design to experimentally examine the effects of oil/dispersed oil, intraspecific genetic diversity, and salinity on juvenile (ca. 25 mm shell height) oyster survivorship and growth during a 21-d exposure in a closed, recirculating system. The genetic effect was weak overall, oil and dispersed oil negatively affected juvenile oyster survivorship, and low salinity mitigated mortality in oil and dispersed oil treatments. Survivorship was about 40% greater in low-salinity than in mesohaline water for both oil and dispersed oil treatments, bringing survivorship in low salinity oil-only treatments to a similar level with low salinity controls (no oil). Oyster growth was minimal after 21 d but appeared to be negatively affected by oil and dispersed oil, and had a significant interaction with salinity. Our results may be informative for future decisions regarding oil spill response activities and suggest that a pulse of low salinity water may be a viable short-term mitigation option for oysters if filtration characteristics, exposure time, and water temperatures are all considered, in addition to weighing the costs and benefits of this type of response on other organisms and habitats.
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11
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Arnaldi KG, Walters LJ, Hoffman EA. Effects of time and harvest on genetic diversity of natural and restored oyster reefs. Restor Ecol 2018. [DOI: 10.1111/rec.12672] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kimberly G. Arnaldi
- Department of Biology; University of Central Florida, 4000 Central Florida Boulevard; Orlando FL 32816 U.S.A
| | - Linda J. Walters
- Department of Biology; University of Central Florida, 4000 Central Florida Boulevard; Orlando FL 32816 U.S.A
| | - Eric A. Hoffman
- Department of Biology; University of Central Florida, 4000 Central Florida Boulevard; Orlando FL 32816 U.S.A
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12
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Abbott JM, DuBois K, Grosberg RK, Williams SL, Stachowicz JJ. Genetic distance predicts trait differentiation at the subpopulation but not the individual level in eelgrass, Zostera marina. Ecol Evol 2018; 8:7476-7489. [PMID: 30151164 PMCID: PMC6106171 DOI: 10.1002/ece3.4260] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/29/2018] [Accepted: 05/15/2018] [Indexed: 11/08/2022] Open
Abstract
Ecological studies often assume that genetically similar individuals will be more similar in phenotypic traits, such that genetic diversity can serve as a proxy for trait diversity. Here, we explicitly test the relationship between genetic relatedness and trait distance using 40 eelgrass (Zostera marina) genotypes from five sites within Bodega Harbor, CA. We measured traits related to nutrient uptake, morphology, biomass and growth, photosynthesis, and chemical deterrents for all genotypes. We used these trait measurements to calculate a multivariate pairwise trait distance for all possible genotype combinations. We then estimated pairwise relatedness from 11 microsatellite markers. We found significant trait variation among genotypes for nearly every measured trait; however, there was no evidence of a significant correlation between pairwise genetic relatedness and multivariate trait distance among individuals. However, at the subpopulation level (sites within a harbor), genetic (FST) and trait differentiation were positively correlated. Our work suggests that pairwise relatedness estimated from neutral marker loci is a poor proxy for trait differentiation between individual genotypes. It remains to be seen whether genomewide measures of genetic differentiation or easily measured "master" traits (like body size) might provide good predictions of overall trait differentiation.
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Affiliation(s)
- Jessica M. Abbott
- Center for Population BiologyUniversity of CaliforniaDavisCalifornia
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
- Institute for Wildlife StudiesArcataCalifornia
| | - Katherine DuBois
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
- Bodega Marine LaboratoryBodega BayCalifornia
| | - Richard K. Grosberg
- Center for Population BiologyUniversity of CaliforniaDavisCalifornia
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
| | - Susan L. Williams
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
- Bodega Marine LaboratoryBodega BayCalifornia
| | - John J. Stachowicz
- Center for Population BiologyUniversity of CaliforniaDavisCalifornia
- Department of Evolution and EcologyUniversity of CaliforniaDavisCalifornia
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Hughes AR, Hanley TC, Byers JE, Grabowski JH, Malek JC, Piehler MF, Kimbro DL. Genetic by environmental variation but no local adaptation in oysters ( Crassostrea virginica). Ecol Evol 2016; 7:697-709. [PMID: 28116064 PMCID: PMC5243187 DOI: 10.1002/ece3.2614] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 10/10/2016] [Accepted: 11/01/2016] [Indexed: 01/19/2023] Open
Abstract
Functional trait variation within and across populations can strongly influence population, community, and ecosystem processes, but the relative contributions of genetic vs. environmental factors to this variation are often not clear, potentially complicating conservation and restoration efforts. For example, local adaptation, a particular type of genetic by environmental (G*E) interaction in which the fitness of a population in its own habitat is greater than in other habitats, is often invoked in management practices, even in the absence of supporting evidence. Despite increasing attention to the potential for G*E interactions, few studies have tested multiple populations and environments simultaneously, limiting our understanding of the spatial consistency in patterns of adaptive genetic variation. In addition, few studies explicitly differentiate adaptation in response to predation from other biological and environmental factors. We conducted a reciprocal transplant experiment of first‐generation eastern oyster (Crassostrea virginica) juveniles from six populations across three field sites spanning 1000 km in the southeastern Atlantic Bight in both the presence and absence of predation to test for G*E variation in this economically valuable and ecologically important species. We documented significant G*E variation in survival and growth, yet there was no evidence for local adaptation. Condition varied across oyster cohorts: Offspring of northern populations had better condition than offspring from the center of our region. Oyster populations in the southeastern Atlantic Bight differ in juvenile survival, growth, and condition, yet offspring from local broodstock do not have higher survival or growth than those from farther away. In the absence of population‐specific performance information, oyster restoration and aquaculture may benefit from incorporating multiple populations into their practices.
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Affiliation(s)
| | | | - James E Byers
- Odum School of Ecology University of Georgia Athens GA USA
| | | | | | - Michael F Piehler
- Institute of Marine Sciences University of North Carolina at Chapel Hill Morehead City NC USA
| | - David L Kimbro
- Marine Science Center Northeastern University Nahant MA USA
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Randall Hughes A, Hanley TC, Schenck FR, Hays CG. Genetic diversity of seagrass seeds influences seedling morphology and biomass. Ecology 2016; 97:3538-3546. [PMID: 27912018 DOI: 10.1002/ecy.1587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/23/2016] [Accepted: 09/13/2016] [Indexed: 11/08/2022]
Abstract
Genetic diversity can influence ecological processes throughout ontogeny, yet whether diversity at early life history stages is important in long-lived taxa with overlapping generations is unclear. Seagrass systems provide some of the best evidence for the ecological effects of genetic diversity among adult shoots, but we do not know if the genetic diversity of seeds and seedlings also influences seagrass ecology. We tested the effects of seagrass (Zostera marina) seed diversity and relatedness on germination success, seedling morphology, and seedling production by comparing experimental assemblages of seeds collected from single reproductive shoots ("monocultures") to assemblages of seeds collected from multiple reproductive shoots ("polycultures"). There was no difference in seedling emergence, yet seedlings from polycultures had larger shoots above and below ground than seedlings from monocultures at the end of the 1-yr experiment. Genetic relatedness of the seedlings predicted some aspects of shoot morphology, with more leaves and longer roots and shoots at intermediate levels of relatedness, regardless of seed diversity. Our results suggest that studies of only adult stages may underestimate the importance of genetic diversity if the benefits at early life history stages continue to accrue throughout the life cycle.
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Affiliation(s)
- A Randall Hughes
- Marine and Environmental Science, Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908, USA
| | - Torrance C Hanley
- Marine and Environmental Science, Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908, USA
| | - Forest R Schenck
- Marine and Environmental Science, Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908, USA
| | - Cynthia G Hays
- Biology Department, Keene State College, Keene, New Hampshire, 03431, USA
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