BRACKEN Matthew's profile
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BRACKEN Matthew

  • Department of Ecology and Evolutionary Biology, University of California, Irvine, California, United States of America
  • Biodiversity, Community ecology, Ecological stoichiometry, Ecosystem functioning, Experimental ecology, Facilitation & Mutualism, Herbivory, Marine ecology
  • recommender

Recommendations:  2

Reviews:  0

Educational and work
Education 1997-2003 Ph.D. in Zoology, Oregon State University 1993-1997 B.S. in Biology (Mathematics Minor), University of Puget Sound (Cum Laude) Employment 2014-now Associate Professor, Department of Ecology and Evolutionary Biology, University of California, Irvine 2013 Associate Professor, Department of Marine and Environmental Sciences, Northeastern University 2011-2013 Assistant Professor, Department of Marine and Environmental Sciences, Northeastern University 2007-2013 Assistant Professor, Department of Biology, Northeastern University 2005-2007 Postdoctoral Scholar, Bodega Marine Laboratory, University of California, Davis 2004-2005 Postdoctoral Scholar, Section of Evolution and Ecology, UC Davis 2003-2004 Visiting Postdoctoral Researcher, Edward Percival Field Station, Kaikoura, New Zealand 2003 Postdoctoral Research Associate, Department of Zoology, Oregon State University 2001-2003 Graduate Research Assistant, Department of Zoology, Oregon State University 1999, 2002 Mellon FoundationGraduate Fellow, University of Canterbury, Christchurch, New Zealand 1998-2001 Graduate Research Fellow, National Science Foundation 1997-2000 Graduate Teaching Assistant, Department of Zoology, Oregon State University

Recommendations:  2

2021-05-06
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Trophic niche of the invasive gregarious species Crepidula fornicata, in relation to ontogenic changes

Recommended by based on reviews by 2 anonymous reviewers

A lack of clear dietary differences between ontogenetic stages of invasive slippersnails provides important insights into resource use and potential inter- and intra-specific competition

The slippersnail (Crepidula fornicata), originally from the eastern coast of North America, has invaded European coastlines from Norway to the Mediterranean Sea [1]. This species is capable of achieving incredibly high densities (up to several thousand individuals per square meter) and likely has major impacts on a variety of community- and ecosystem-level processes, including alteration of carbon and nitrogen fluxes and competition with native suspension feeders [2].

Given this potential for competition, it is important to understand the diet of C. fornicata and its potential overlap with native species. However, previous research on the diet of C. fornicata and related species suggests that the types of food consumed may change with age [3, 4]. This species has an unusual reproductive strategy. It is a sequential hermaphrodite, which begins life as a somewhat mobile male but eventually slows down to become sessile. Sessile individuals form stacks of up to 10 or more individuals, with larger individuals on the bottom of the stack, and decreasingly smaller individuals piled on top. Snails at the bottom of the stack are female, whereas snails at the top of the stack are male; when the females die, the largest males become female [5]. Thus, understanding these potential ontogenetic dietary shifts has implications for both intraspecific (juvenile vs. male vs. female) and interspecific competition associated with an abundant, invasive species.

To this end, Androuin and colleagues evaluated the stable-isotope (d13C and d15N) and fatty-acid profiles of food sources and different life-history stages of C. fornicata [6]. Based on previous work highlighting the potential for life-history changes in the diet of this species [3,4], they hypothesized that C. fornicata would shift its diet as it aged and predicted that this shift would be reflected in changes in its stable-isotope and fatty-acid profiles. The authors found that potential food sources (biofilm, suspended particulate organic matter, and superficial sedimentary organic matter) differed substantially in both stable-isotope and fatty-acid signatures. However, whereas fatty-acid profiles changed substantially with age, there was no shift in the stable-isotope signatures. Because stable-isotope differences between food sources were not reflected in differences between life-history stages, the authors conservatively concluded that there was insufficient evidence for a diet shift with age. The ontogenetic shifts in fatty-acid profiles were intriguing, but the authors suggested that these reflected age-related physiological changes rather than changes in diet.

The authors’ work highlights the need to consider potential changes in the roles of invasive species with age, especially when evaluating interactions with native species. In this case, C. fornicata consumed a variety of food sources, including both benthic and particulate organic matter, regardless of age. The carbon stable-isotope signature of C. fornicata overlaps with those of several native suspension- and deposit-feeding species in the region [7], suggesting the possibility of resource competition, especially given the high abundances of this invader. This contribution demonstrates the potential difficulty of characterizing the impacts of an abundant invasive species with a complex life-history strategy. Like many invasive species, C. fornicata appears to be a dietary generalist, which likely contributes to its success in establishing and thriving in a variety of locations [8].

 

References

[1] Blanchard M (1997) Spread of the slipper limpet Crepidula fornicata (L. 1758) in Europe. Current state dans consequences. Scientia Marina, 61, 109–118. Open Access version : https://archimer.ifremer.fr/doc/00423/53398/54271.pdf

[2] Martin S, Thouzeau G, Chauvaud L, Jean F, Guérin L, Clavier J (2006) Respiration, calcification, and excretion of the invasive slipper limpet, Crepidula fornicata L.: Implications for carbon, carbonate, and nitrogen fluxes in affected areas. Limnology and Oceanography, 51, 1996–2007. https://doi.org/10.4319/lo.2006.51.5.1996

[3] Navarro JM, Chaparro OR (2002) Grazing–filtration as feeding mechanisms in motile specimens of Crepidula fecunda (Gastropoda: Calyptraeidae). Journal of Experimental Marine Biology and Ecology, 270, 111–122. https://doi.org/10.1016/S0022-0981(02)00013-8

[4] Yee AK, Padilla DK (2015) Allometric Scaling of the Radula in the Atlantic Slippersnail Crepidula fornicata. Journal of Shellfish Research, 34, 903–907. https://doi.org/10.2983/035.034.0320

[5] Collin R (1995) Sex, Size, and Position: A Test of Models Predicting Size at Sex Change in the Protandrous Gastropod Crepidula fornicata. The American Naturalist, 146, 815–831. https://doi.org/10.1086/285826

[6] Androuin T, Dubois SF, Hubas C, Lefebvre G, Grand FL, Schaal G, Carlier A (2021) Trophic niche of the invasive gregarious species Crepidula fornicata, in relation to ontogenic changes. bioRxiv, 2020.07.30.229021, ver. 4 peer-reviewed and recommended by Peer Community in Ecology. https://doi.org/10.1101/2020.07.30.229021

[7] Dauby P, Khomsi A, Bouquegneau J-M (1998) Trophic Relationships within Intertidal Communities of the Brittany Coasts: A Stable Carbon Isotope Analysis. Journal of Coastal Research, 14, 1202–1212. Retrieved May 4, 2021, from http://www.jstor.org/stable/4298880

[8] Machovsky-Capuska GE, Senior AM, Simpson SJ, Raubenheimer D (2016) The Multidimensional Nutritional Niche. Trends in Ecology & Evolution, 31, 355–365. https://doi.org/10.1016/j.tree.2016.02.009

 

2019-02-21
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Photosynthesis of Laminaria digitata during the immersion and emersion periods of spring tidal cycles during hot, sunny weather

Recommended by based on reviews by 2 anonymous reviewers

Evaluating physiological responses of a kelp to environmental changes at its vulnerable equatorward range limit

Understanding processes at species’ range limits is of paramount importance in an era of global change. For example, the boreal kelp Laminaria digitata, which dominates low intertidal and shallow subtidal rocky reefs in northwestern Europe, is declining in the equatorward portion of its range [1]. In this contribution, Migné and colleagues [2] focus on L. digitata near its southern range limit on the coast of France and use a variety of techniques to paint a complete picture of the physiological responses of the kelp to environmental changes. Importantly, and in contrast to earlier work on the species which focused on subtidal individuals (e.g. [3]), Migné et al. [2] describe responses not only in the most physiologically stressful portion of the species’ range but also in the most stressful portion of its local environment: the upper portion of its zone on the shoreline, where it is periodically exposed to aerial conditions and associated thermal and desiccation stresses.
The authors show that whereas L. digitata possesses mechanisms to protect it from irradiance stress at low tide, these mechanisms are not sufficient to prevent damage to photosynthetic pathways (e.g., reduction in optimal quantum yields of photosystem II). This species experiences severe heat stress associated with mid-day low tides during the summer, and the cumulative damage associated with these stresses is likely associated with the range contraction that is currently underway. Given the important role that L. digitata plays as food and habitat for other organisms, its loss will have cascading impacts on community structure and ecosystem functioning. Understanding the mechanisms underlying these declines is essential to understanding the impacts of climate change on species, communities, and ecosystems.

References

[1] Raybaud, V., Beaugrand, G., Goberville, E., Delebecq, G., Destombe, C., Valero, M., Davoult, D., Morin, P. & Gevaert, F. (2013). Decline in kelp in west Europe and climate. PloS one, 8(6), e66044. doi: 10.1371/journal.pone.0066044
[2] Delebecq, G., Davoult, D., Menu, D., Janquin, M. A., Migné, A., Dauvin, J. C., & Gevaert, F. (2011). In situ photosynthetic performance of Laminaria digitata (Phaeophyceae) during spring tides in Northern Brittany. CBM-Cahiers de Biologie Marine, 52(4), 405. doi: 10.21411/CBM.A.C9EE91F
[3] Migné, A., Delebecq, G., Davoult, D., Spilmont, N., Menu, D., Janquin, M.-A., and Gevaert, F. (2019). Photosynthesis of Laminaria digitata during the immersion and emersion periods of spring tidal cycles during hot, sunny weather. Hal, 01827565, ver. 4 peer-reviewed and recommended by PCI Ecology. hal-01827565

avatar

BRACKEN Matthew

  • Department of Ecology and Evolutionary Biology, University of California, Irvine, California, United States of America
  • Biodiversity, Community ecology, Ecological stoichiometry, Ecosystem functioning, Experimental ecology, Facilitation & Mutualism, Herbivory, Marine ecology
  • recommender

Recommendations:  2

Reviews:  0

Educational and work
Education 1997-2003 Ph.D. in Zoology, Oregon State University 1993-1997 B.S. in Biology (Mathematics Minor), University of Puget Sound (Cum Laude) Employment 2014-now Associate Professor, Department of Ecology and Evolutionary Biology, University of California, Irvine 2013 Associate Professor, Department of Marine and Environmental Sciences, Northeastern University 2011-2013 Assistant Professor, Department of Marine and Environmental Sciences, Northeastern University 2007-2013 Assistant Professor, Department of Biology, Northeastern University 2005-2007 Postdoctoral Scholar, Bodega Marine Laboratory, University of California, Davis 2004-2005 Postdoctoral Scholar, Section of Evolution and Ecology, UC Davis 2003-2004 Visiting Postdoctoral Researcher, Edward Percival Field Station, Kaikoura, New Zealand 2003 Postdoctoral Research Associate, Department of Zoology, Oregon State University 2001-2003 Graduate Research Assistant, Department of Zoology, Oregon State University 1999, 2002 Mellon FoundationGraduate Fellow, University of Canterbury, Christchurch, New Zealand 1998-2001 Graduate Research Fellow, National Science Foundation 1997-2000 Graduate Teaching Assistant, Department of Zoology, Oregon State University