Small scale habitat effects on anthropogenic litter material and sources in a coastal lagoon system:
- Velez, Nadja, Nicastro, Katy R, McQuaid, Christopher D, Zardi, Gerardi I
- Authors: Velez, Nadja , Nicastro, Katy R , McQuaid, Christopher D , Zardi, Gerardi I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160489 , vital:40450 , https://doi.org/10.1016/j.marpolbul.2020.111689
- Description: Anthropogenic litter is ubiquitous throughout marine ecosystems, but its abundance and distribution are driven by complex interactions of distinct environmental factors and thus can be extremely heterogeneous. Here we compare the extent of anthropogenic litter pollution at a sheltered lagoon habitat and nearby open coast sites. Monthly surveys over a period of five months showed that both the types and sources of litter always differed significantly between lagoon and open coast sites.
- Full Text:
Small scale habitat effects on anthropogenic litter material and sources in a coastal lagoon system:
- Authors: Velez, Nadja , Nicastro, Katy R , McQuaid, Christopher D , Zardi, Gerardi I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160489 , vital:40450 , https://doi.org/10.1016/j.marpolbul.2020.111689
- Description: Anthropogenic litter is ubiquitous throughout marine ecosystems, but its abundance and distribution are driven by complex interactions of distinct environmental factors and thus can be extremely heterogeneous. Here we compare the extent of anthropogenic litter pollution at a sheltered lagoon habitat and nearby open coast sites. Monthly surveys over a period of five months showed that both the types and sources of litter always differed significantly between lagoon and open coast sites.
- Full Text:
Evidence for rangewide panmixia despite multiple barriers to dispersal in a marine mussel
- Lourenço, Carla R, Nicastro, Katy R, McQuaid, Christopher D, Chefaoui, Rosa M, Assis, Jorge, Taleb, Mohammed Z, Zardi, Gerardo I
- Authors: Lourenço, Carla R , Nicastro, Katy R , McQuaid, Christopher D , Chefaoui, Rosa M , Assis, Jorge , Taleb, Mohammed Z , Zardi, Gerardo I
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59952 , vital:27714 , doi:10.1038/s41598-017-10753-9
- Description: Oceanographic features shape the distributional and genetic patterns of marine species by interrupting or promoting connections among populations. Although general patterns commonly arise, distributional ranges and genetic structure are species-specific and do not always comply with the expected trends. By applying a multimarker genetic approach combined with Lagrangian particle simulations (LPS) we tested the hypothesis that oceanographic features along northeastern Atlantic and Mediterranean shores influence dispersal potential and genetic structure of the intertidal mussel Perna perna. Additionally, by performing environmental niche modelling we assessed the potential and realized niche of P. perna along its entire native distributional range and the environmental factors that best explain its realized distribution. Perna perna showed evidence of panmixia across 4,000 km despite several oceanographic breaking points detected by LPS. This is probably the result of a combination of life history traits, continuous habitat availability and stepping-stone dynamics. Moreover, the niche modelling framework depicted minimum sea surface temperatures (SST) as the major factor shaping P. perna distributional range limits along its native areas. Forthcoming warming SST is expected to further change these limits and allow the species to expand its range polewards though this may be accompanied by retreat from warmer areas.
- Full Text:
- Authors: Lourenço, Carla R , Nicastro, Katy R , McQuaid, Christopher D , Chefaoui, Rosa M , Assis, Jorge , Taleb, Mohammed Z , Zardi, Gerardo I
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59952 , vital:27714 , doi:10.1038/s41598-017-10753-9
- Description: Oceanographic features shape the distributional and genetic patterns of marine species by interrupting or promoting connections among populations. Although general patterns commonly arise, distributional ranges and genetic structure are species-specific and do not always comply with the expected trends. By applying a multimarker genetic approach combined with Lagrangian particle simulations (LPS) we tested the hypothesis that oceanographic features along northeastern Atlantic and Mediterranean shores influence dispersal potential and genetic structure of the intertidal mussel Perna perna. Additionally, by performing environmental niche modelling we assessed the potential and realized niche of P. perna along its entire native distributional range and the environmental factors that best explain its realized distribution. Perna perna showed evidence of panmixia across 4,000 km despite several oceanographic breaking points detected by LPS. This is probably the result of a combination of life history traits, continuous habitat availability and stepping-stone dynamics. Moreover, the niche modelling framework depicted minimum sea surface temperatures (SST) as the major factor shaping P. perna distributional range limits along its native areas. Forthcoming warming SST is expected to further change these limits and allow the species to expand its range polewards though this may be accompanied by retreat from warmer areas.
- Full Text:
Love thy neighbour : group properties of gaping behaviour in mussel aggregations
- Nicastro, Katy R, Zardi, Gerardo I, McQuaid, Christopher D, Pearson, Gareth A, Serrão, Ester A
- Authors: Nicastro, Katy R , Zardi, Gerardo I , McQuaid, Christopher D , Pearson, Gareth A , Serrão, Ester A
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6841 , http://hdl.handle.net/10962/d1010991
- Description: By associating closely with others to form a group, an animal can benefit from a number of advantages including reduced risk of predation, amelioration of environmental conditions, and increased reproductive success, but at the price of reduced resources. Although made up of individual members, an aggregation often displays novel effects that do not manifest at the level of the individual organism. Here we show that very simple behaviour in intertidal mussels shows new effects in dense aggregations but not in isolated individuals. Perna perna and Mytilus galloprovincialis are gaping (periodic valve movement during emersion) and non-gaping mussels respectively. P. perna gaping behaviour had no effect on body temperatures of isolated individuals, while it led to increased humidity and decreased temperatures in dense groups (beds). Gaping resulted in cooler body temperatures for P. perna than M. galloprovincialis when in aggregations, while solitary individuals exhibited the highest temperatures. Gradients of increasing body temperature were detected from the center to edges of beds, but M. galloprovincialis at the edge had the same temperature as isolated individuals. Furthermore, a field study showed that during periods of severe heat stress, mortality rates of mussels within beds of the gaping P. perna were lower than those of isolated individuals or within beds of M. galloprovincialis, highlighting the determinant role of gaping on fitness and group functioning. We demonstrate that new effects of very simple individual behaviour lead to amelioration of abiotic conditions at the aggregation level and that these effects increase mussel resistance to thermal stress.
- Full Text:
- Authors: Nicastro, Katy R , Zardi, Gerardo I , McQuaid, Christopher D , Pearson, Gareth A , Serrão, Ester A
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6841 , http://hdl.handle.net/10962/d1010991
- Description: By associating closely with others to form a group, an animal can benefit from a number of advantages including reduced risk of predation, amelioration of environmental conditions, and increased reproductive success, but at the price of reduced resources. Although made up of individual members, an aggregation often displays novel effects that do not manifest at the level of the individual organism. Here we show that very simple behaviour in intertidal mussels shows new effects in dense aggregations but not in isolated individuals. Perna perna and Mytilus galloprovincialis are gaping (periodic valve movement during emersion) and non-gaping mussels respectively. P. perna gaping behaviour had no effect on body temperatures of isolated individuals, while it led to increased humidity and decreased temperatures in dense groups (beds). Gaping resulted in cooler body temperatures for P. perna than M. galloprovincialis when in aggregations, while solitary individuals exhibited the highest temperatures. Gradients of increasing body temperature were detected from the center to edges of beds, but M. galloprovincialis at the edge had the same temperature as isolated individuals. Furthermore, a field study showed that during periods of severe heat stress, mortality rates of mussels within beds of the gaping P. perna were lower than those of isolated individuals or within beds of M. galloprovincialis, highlighting the determinant role of gaping on fitness and group functioning. We demonstrate that new effects of very simple individual behaviour lead to amelioration of abiotic conditions at the aggregation level and that these effects increase mussel resistance to thermal stress.
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Sand stress as a non-determinant of habitat segregation of indigenous (Perna perna) and invasive (Mytilus galloprovincialis) mussels in South Africa
- Zardi, Gerardo I, Nicastro, Katy R, Porri, Francesca, McQuaid, Christopher D
- Authors: Zardi, Gerardo I , Nicastro, Katy R , Porri, Francesca , McQuaid, Christopher D
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6946 , http://hdl.handle.net/10962/d1011974
- Description: Periodical sand inundation influences diversity and distribution of intertidal species throughout the world. This study investigates the effect of sand stress on survival and on habitat segregation of the two dominant mussel species living in South Africa, the invasive Mytilus galloprovincialis and the indigenous Perna perna. P. perna occupies a lower intertidal zone which, monthly surveys over 1.5 years showed, is covered by sand for longer periods than the higher M. galloprovincialis zone. Despite this, when buried under sand, P. perna mortality rates were significantly higher than those of M. galloprovincialis in both laboratory and in field experiments. Under anoxic condition, P. perna mortality rates were still significantly higher than those for M. galloprovincialis, but both species died later than when exposed to sand burial, underlining the importance of the physical action of sand on mussel internal organs. When buried, both species accumulate sediments within the shell valves while still alive, but the quantities are much greater for P. perna. This suggests that P. perna gills are more severely damaged by sand abrasion and could explain its higher mortality rates. M. galloprovincialis has longer labial palps than P. perna, indicating a higher particle sorting ability and consequently explaining its lower mortality rates when exposed to sand in suspension. Habitat segregation is often explained by physiological tolerances, but in this case, such explanations fail. Although sand stress strongly affects the survival of the two species, it does not explain their vertical zonation. Contrary to our expectations, the species that is less well adapted to cope with sand stress maintains dominance in a habitat where such stress is high.
- Full Text:
- Authors: Zardi, Gerardo I , Nicastro, Katy R , Porri, Francesca , McQuaid, Christopher D
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6946 , http://hdl.handle.net/10962/d1011974
- Description: Periodical sand inundation influences diversity and distribution of intertidal species throughout the world. This study investigates the effect of sand stress on survival and on habitat segregation of the two dominant mussel species living in South Africa, the invasive Mytilus galloprovincialis and the indigenous Perna perna. P. perna occupies a lower intertidal zone which, monthly surveys over 1.5 years showed, is covered by sand for longer periods than the higher M. galloprovincialis zone. Despite this, when buried under sand, P. perna mortality rates were significantly higher than those of M. galloprovincialis in both laboratory and in field experiments. Under anoxic condition, P. perna mortality rates were still significantly higher than those for M. galloprovincialis, but both species died later than when exposed to sand burial, underlining the importance of the physical action of sand on mussel internal organs. When buried, both species accumulate sediments within the shell valves while still alive, but the quantities are much greater for P. perna. This suggests that P. perna gills are more severely damaged by sand abrasion and could explain its higher mortality rates. M. galloprovincialis has longer labial palps than P. perna, indicating a higher particle sorting ability and consequently explaining its lower mortality rates when exposed to sand in suspension. Habitat segregation is often explained by physiological tolerances, but in this case, such explanations fail. Although sand stress strongly affects the survival of the two species, it does not explain their vertical zonation. Contrary to our expectations, the species that is less well adapted to cope with sand stress maintains dominance in a habitat where such stress is high.
- Full Text:
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