Limits...
Oceanographic Conditions Limit the Spread of a Marine Invader along Southern African Shores.

Assis J, Zupan M, Nicastro KR, Zardi GI, McQuaid CD, Serrão EA - PLoS ONE (2015)

Bottom Line: The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa.On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species.The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role.

View Article: PubMed Central - PubMed

Affiliation: Center of Marine Sciences, University of Algarve, Faro, Portugal.

ABSTRACT
Invasive species can affect the function and structure of natural ecological communities, hence understanding and predicting their potential for spreading is a major ecological challenge. Once established in a new region, the spread of invasive species is largely controlled by their dispersal capacity, local environmental conditions and species interactions. The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa. Its distribution there has expanded rapidly and extensively since the 1970s, however, over the last decade its spread has ceased. In this study, we coupled broad scale field surveys, Ecological Niche Modelling (ENM) and Lagrangian Particle Simulations (LPS) to assess the current invaded distribution of M. galloprovincialis in southern Africa and to evaluate what prevents further spread of this species. Results showed that all environmentally suitable habitats in southern Africa have been occupied by the species. This includes rocky shores between Rocky Point in Namibia and East London in South Africa (approx. 2800 km) and these limits coincide with the steep transitions between cool-temperate and subtropical-warmer climates, on both west and southeast African coasts. On the west coast, simulations of drifting larvae almost entirely followed the northward and offshore direction of the Benguela current, creating a clear dispersal barrier by advecting larvae away from the coast. On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species. The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role.

No MeSH data available.


Related in: MedlinePlus

(a) Records of occurrence for M. galloprovincialis throughout the southern African coast (Red dots for presence and blue dots for absence). (b) Reclassified ensemble showing the occurrence of M. galloprovincialis for the present (2000–2010). Numbers show Regions Of Interest: ROI 1. Rocky Point, ROI 2. Walvis Bay, ROI 3. Sossusvlei, ROI 4. Elizabeth Bay, ROI 5. Cape Town, ROI 6. Port Elizabeth, ROI 7. East London, ROI 8. Durban. The dashed squares indicate those regions where the Lagrangian Particle Simulations where performed: the west coast, from Capulo to Walvis Bay, and the southeast coast, from St Francis Bay to Beira. Credits for the background of both maps: General Bathymetric Chart of the Oceans (GEBCO).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4482700&req=5

pone.0128124.g001: (a) Records of occurrence for M. galloprovincialis throughout the southern African coast (Red dots for presence and blue dots for absence). (b) Reclassified ensemble showing the occurrence of M. galloprovincialis for the present (2000–2010). Numbers show Regions Of Interest: ROI 1. Rocky Point, ROI 2. Walvis Bay, ROI 3. Sossusvlei, ROI 4. Elizabeth Bay, ROI 5. Cape Town, ROI 6. Port Elizabeth, ROI 7. East London, ROI 8. Durban. The dashed squares indicate those regions where the Lagrangian Particle Simulations where performed: the west coast, from Capulo to Walvis Bay, and the southeast coast, from St Francis Bay to Beira. Credits for the background of both maps: General Bathymetric Chart of the Oceans (GEBCO).

Mentions: The field surveys provided 104 georeferenced records for M. galloprovincialis in southern Africa. For modelling purposes, this dataset was enhanced with 170 additional records from native ranges derived from field surveys in North Africa and Southern Europe, the available literature and an electronic database (Fig 1A; S1 Text).


Oceanographic Conditions Limit the Spread of a Marine Invader along Southern African Shores.

Assis J, Zupan M, Nicastro KR, Zardi GI, McQuaid CD, Serrão EA - PLoS ONE (2015)

(a) Records of occurrence for M. galloprovincialis throughout the southern African coast (Red dots for presence and blue dots for absence). (b) Reclassified ensemble showing the occurrence of M. galloprovincialis for the present (2000–2010). Numbers show Regions Of Interest: ROI 1. Rocky Point, ROI 2. Walvis Bay, ROI 3. Sossusvlei, ROI 4. Elizabeth Bay, ROI 5. Cape Town, ROI 6. Port Elizabeth, ROI 7. East London, ROI 8. Durban. The dashed squares indicate those regions where the Lagrangian Particle Simulations where performed: the west coast, from Capulo to Walvis Bay, and the southeast coast, from St Francis Bay to Beira. Credits for the background of both maps: General Bathymetric Chart of the Oceans (GEBCO).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482700&req=5

pone.0128124.g001: (a) Records of occurrence for M. galloprovincialis throughout the southern African coast (Red dots for presence and blue dots for absence). (b) Reclassified ensemble showing the occurrence of M. galloprovincialis for the present (2000–2010). Numbers show Regions Of Interest: ROI 1. Rocky Point, ROI 2. Walvis Bay, ROI 3. Sossusvlei, ROI 4. Elizabeth Bay, ROI 5. Cape Town, ROI 6. Port Elizabeth, ROI 7. East London, ROI 8. Durban. The dashed squares indicate those regions where the Lagrangian Particle Simulations where performed: the west coast, from Capulo to Walvis Bay, and the southeast coast, from St Francis Bay to Beira. Credits for the background of both maps: General Bathymetric Chart of the Oceans (GEBCO).
Mentions: The field surveys provided 104 georeferenced records for M. galloprovincialis in southern Africa. For modelling purposes, this dataset was enhanced with 170 additional records from native ranges derived from field surveys in North Africa and Southern Europe, the available literature and an electronic database (Fig 1A; S1 Text).

Bottom Line: The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa.On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species.The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role.

View Article: PubMed Central - PubMed

Affiliation: Center of Marine Sciences, University of Algarve, Faro, Portugal.

ABSTRACT
Invasive species can affect the function and structure of natural ecological communities, hence understanding and predicting their potential for spreading is a major ecological challenge. Once established in a new region, the spread of invasive species is largely controlled by their dispersal capacity, local environmental conditions and species interactions. The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa. Its distribution there has expanded rapidly and extensively since the 1970s, however, over the last decade its spread has ceased. In this study, we coupled broad scale field surveys, Ecological Niche Modelling (ENM) and Lagrangian Particle Simulations (LPS) to assess the current invaded distribution of M. galloprovincialis in southern Africa and to evaluate what prevents further spread of this species. Results showed that all environmentally suitable habitats in southern Africa have been occupied by the species. This includes rocky shores between Rocky Point in Namibia and East London in South Africa (approx. 2800 km) and these limits coincide with the steep transitions between cool-temperate and subtropical-warmer climates, on both west and southeast African coasts. On the west coast, simulations of drifting larvae almost entirely followed the northward and offshore direction of the Benguela current, creating a clear dispersal barrier by advecting larvae away from the coast. On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species. The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role.

No MeSH data available.


Related in: MedlinePlus