Congruence between fine-scale genetic breaks and dispersal potential in an estuarine seaweed across multiple transition zones:
- Authors: Nicastro, Katy R , Assis, Jorge , Serrão, Ester A , Pearson, Gareth A , Neiva, Joao , Valero, Myriam , Jacinto, Rita , Zardi, Gerardo I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149873 , vital:38908 , https://0-doi.org.wam.seals.ac.za/10.1093/icesjms/fsz179
- Description: Genetic structure in biogeographical transition zones can be shaped by several factors including limited dispersal across barriers, admixture following secondary contact, differential selection, and mating incompatibility. A striking example is found in Northwest France and Northwest Spain, where the estuarine seaweed Fucus ceranoides L. exhibits sharp, regional genetic clustering. This pattern has been related to historical population fragmentation and divergence into distinct glacial refugia, followed by post-glacial expansion and secondary contact. The contemporary persistence of sharp ancient genetic breaks between nearby estuaries has been attributed to prior colonization effects (density barriers) but the effect of oceanographic barriers has not been tested. Here, through a combination of mesoscale sampling (15 consecutive populations) and population genetic data (mtIGS) in NW France, we define regional genetic disjunctions similar to those described in NW Iberia. Most importantly, using high resolution dispersal simulations for Brittany and Iberian populations, we provide evidence for a central role of contemporary hydrodynamics in maintaining genetic breaks across these two major biogeographic transition zones. Our findings further show the importance of a comprehensive understanding of oceanographic regimes in hydrodynamically complex coastal regions to explain the maintenance of sharp genetic breaks along continuously populated coastlines.
- Full Text:
- Date Issued: 2020
Microplastic leachates induce species-specific trait strengthening in intertidal mussels:
- Authors: Seuront, Laurent , Nicastro, Katy , McQuaid, Christopher D , Zardi, Gerardo I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158200 , vital:40162 , https://0-doi.org.wam.seals.ac.za/10.1002/eap.2222. https://doi.org/10.5061/dryad.905qftthq
- Description: Plastic pollution is ubiquitous with increasing recognition of its direct effects on species’ fitness. Little is known, however, about its more subtle effects, including the influence of plastic pollution on the morphological, functional and behavioural traits of organisms that are central to their ability to withstand disturbances. Among the least obvious but most pernicious forms of plastic-associated pollution are the chemicals that leach from microplastics. Here, we investigate how such leachates influence species’ traits by assessing functional trait compensation across four species of intertidal mussels, through investigations of byssal thread production, movement and aggregation behaviour for mussels held in natural seawater or seawater contaminated by microplastic leachates.
- Full Text:
- Date Issued: 2020
Species-specific plastic accumulation in the sediment and canopy of coastal vegetated habitats:
- Authors: Cozzolino, Lorenzo , Nicastro, Katy R , Zardi, Gerardo I , de los Santos, Carmen B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149410 , vital:38848 , https://doi.org/10.1016/j.scitotenv.2020.138018
- Description: Plastic waste has become ubiquitous in ecosystems worldwide. Few, recent studies report evidence of coastal vegetated habitats acting as sink for plastics, yet assessments have been completed either for macro or microplastics and focussing on just one type of vegetated habitat.
- Full Text:
- Date Issued: 2020