scholarly journals Local Drivers of Change in Southern Ocean Ecosystems: Human Activities and Policy Implications

2021 ◽  
Vol 9 ◽  
Author(s):  
Susie M. Grant ◽  
Cath L. Waller ◽  
Simon A. Morley ◽  
David K. A. Barnes ◽  
Madeleine J. Brasier ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Human Activities ◽  
Marine Mammals ◽  
Regional Scale ◽  
Policy Implications ◽  
Ecological Change ◽  
Indigenous Species ◽  
Ocean Ecosystems ◽  
Projected Changes ◽  
Non Indigenous Species

Local drivers are human activities or processes that occur in specific locations, and cause physical or ecological change at the local or regional scale. Here, we consider marine and land-derived pollution, non-indigenous species, tourism and other human visits, exploitation of marine resources, recovery of marine mammals, and coastal change as a result of ice loss, in terms of their historic and current extent, and their interactions with the Southern Ocean environment. We summarise projected increases or decreases in the influence of local drivers, and projected changes to their geographic range, concluding that the influence of non-indigenous species, fishing, and the recovery of marine mammals are predicted to increase in the future across the Southern Ocean. Local drivers can be managed regionally, and we identify existing governance frameworks as part of the Antarctic Treaty System and other instruments which may be employed to mitigate or limit their impacts on Southern Ocean ecosystems.

scholarly journals Responses of Southern Ocean Seafloor Habitats and Communities to Global and Local Drivers of Change

2021 ◽  
Vol 8 ◽  
Author(s):  
Madeleine J. Brasier ◽  
David Barnes ◽  
Narissa Bax ◽  
Angelika Brandt ◽  
Anne B. Christianson ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Indigenous Species ◽  
Drivers Of Change ◽  
Regional Warming ◽  
Commercial Fish ◽  
Key Species ◽  
Antarctic Shelf ◽  
Non Indigenous Species ◽  
The Antarctic ◽  
Slow Growing

Knowledge of life on the Southern Ocean seafloor has substantially grown since the beginning of this century with increasing ship-based surveys and regular monitoring sites, new technologies and greatly enhanced data sharing. However, seafloor habitats and their communities exhibit high spatial variability and heterogeneity that challenges the way in which we assess the state of the Southern Ocean benthos on larger scales. The Antarctic shelf is rich in diversity compared with deeper water areas, important for storing carbon (“blue carbon”) and provides habitat for commercial fish species. In this paper, we focus on the seafloor habitats of the Antarctic shelf, which are vulnerable to drivers of change including increasing ocean temperatures, iceberg scour, sea ice melt, ocean acidification, fishing pressures, pollution and non-indigenous species. Some of the most vulnerable areas include the West Antarctic Peninsula, which is experiencing rapid regional warming and increased iceberg-scouring, subantarctic islands and tourist destinations where human activities and environmental conditions increase the potential for the establishment of non-indigenous species and active fishing areas around South Georgia, Heard and MacDonald Islands. Vulnerable species include those in areas of regional warming with low thermal tolerance, calcifying species susceptible to increasing ocean acidity as well as slow-growing habitat-forming species that can be damaged by fishing gears e.g., sponges, bryozoan, and coral species. Management regimes can protect seafloor habitats and key species from fishing activities; some areas will need more protection than others, accounting for specific traits that make species vulnerable, slow growing and long-lived species, restricted locations with optimum physiological conditions and available food, and restricted distributions of rare species. Ecosystem-based management practices and long-term, highly protected areas may be the most effective tools in the preservation of vulnerable seafloor habitats. Here, we focus on outlining seafloor responses to drivers of change observed to date and projections for the future. We discuss the need for action to preserve seafloor habitats under climate change, fishing pressures and other anthropogenic impacts.

scholarly journals Are there Invasive Planktonic Microbes?

2019 ◽  
Vol 2 (2) ◽  
Keyword(s):  
Natural Population ◽  
Human Activities ◽  
Environmental Changes ◽  
Common Species ◽  
Species Level ◽  
Indigenous Species ◽  
Introduced Populations ◽  
Interannual Fluctuations ◽  
Non Indigenous Species ◽  
Gymnodinium Catenatum

The translocation of species by human activities is a problem that increases with the globalization. However, the examples of non-indigenous or exotic planktonic microbes can be questioned as they predominantly have cosmopolitan distributions and natural mechanisms for wide dispersion. In reality, the categorization of any species as non-indigenous requires solving two difficult issues: knowledge of where the ‘natural’ population is, and demonstration of a substantial geographic discontinuity between the supposed source and the introduced populations. With regard to planktonic microorganisms, a non-indigenous taxon could have been previously unnoticed during routine microscopical analyses due to: A) difficult identification at the species level in routine observations such as for the diatoms (Pseudo-nitzschia, Skeletonema, Thalassiosira, Pleurosigma), unarmoured dinoflagellates (Karenia, Karlodinium) and Raphidophytes, and B) species with strong interannual fluctuations of abundance, only detected during bloom periods when they are misinterpreted as newcomers (i.e., Coscinodiscus wailesii or Trieres chinensis, junior synonyms of C. cylindricus and T. regia, respectively, or Gymnodinium catenatum). Rather than attempting to add to the lists of non-indigenous species with planktonic microbes, the monitoring surveys should also pay attention in the less common species with important fluctuations of abundance, independent of tentative labels as exotic or indigenous, because they are potentially useful as bio-indicators of environmental changes.

scholarly journals Marine richness and gradients at Deception Island, Antarctica

2008 ◽  
Vol 20 (3) ◽  
pp. 271-280 ◽  
Author(s):  
David K.A. Barnes ◽  
Katrin Linse ◽  
Peter Enderlein ◽  
Dan Smale ◽  
Keiron P.P. Fraser ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Marine Species ◽  
South Shetland Islands ◽  
Indigenous Species ◽  
Deception Island ◽  
Shetland Islands ◽  
Antarctic Marine ◽  
Planktotrophic Larvae ◽  
Non Indigenous Species ◽  
Total Species

AbstractStudies of the recovery of the fauna following the 1967–70 eruptions at Deception Island, South Shetland Islands, have made it one of the best-studied marine sites of the Southern Ocean for biodiversity. Using SCUBA we surveyed the mega- and macro-epifauna of its subtidal zones in the entrance (Neptune's Bellows), immediately inside the caldera (Whaler's Bay) and well within the caldera (Fumarole Bay). Richness declined from 10 phyla, 13 classes and 35 species at Neptune's Bellows to three phyla, four classes and five species in Whaler's Bay and just two phyla, classes and species at Fumarole Bay. Amongst the 35 species we found at Neptune's Bellows, 14 were previously unrecorded from Deception Island. Despite many ship visits and amongst the warmest sea temperatures in the Southern Ocean, the Non Indigenous Species (NIS) algae were not found in our survey. Deception Island has been recolonized considerably since the recent eruptions, but many taxa are still very poorly represented and the colonizers present are mainly those with planktotrophic larvae. Examination of the literature revealed that to date 163 named marine species have been found within the caldera as well as at least 50 more morphospecies, which are yet to be identified. Species accumulation has consistently increased across eight recent samples reported and the number of species reported there is likely to reach 300 when taxa such as the nematodes are identified to species level. This represents a first meaningful total species estimate for an Antarctic marine area and, as the site is comparatively impoverished, indicates how rich the surrounding Antarctic shelf must be.

scholarly journals An introgression breakthrough left by an anthropogenic contact between two ascidians

2021 ◽  
Author(s):  
Alan Le Moan ◽  
Charlotte Roby ◽  
Christelle Fraisse ◽  
Claire Daguin-Thiebaut ◽  
Nicolas Bierne ◽  
...  
Keyword(s):  
Regional Scale ◽  
Indigenous Species ◽  
North East ◽  
The North ◽  
Allopatric Divergence ◽  
In The Wild ◽  
Speciation Continuum ◽  
Non Indigenous Species ◽  
Evolutionary Consequences ◽  
First And Second Generation

Human-driven translocations of species have diverse evolutionary consequences such as promoting hybridization between previously geographically isolated taxa. This is well-illustrated by the solitary tunicate, Ciona robusta, native to the North East Pacific and introduced in the North East Atlantic. It is now co-occurring with its congener C. intestinalis in the English Channel, and C. roulei in the Mediterranean Sea. Despite their long allopatric divergence, first and second generation crosses showed a high hybridization success between the introduced and native taxa in the laboratory. However, previous genetic studies failed to provide evidence of recent hybridization between C. robusta and C. intestinalis in the wild. Using SNPs obtained from ddRAD-sequencing of 397 individuals from 26 populations, we further explored the genome-wide population structure of the native Ciona taxa. We first confirmed results documented in previous studies, notably i) a chaotic genetic structure at regional scale, and ii) a high genetic similarity between C. roulei and C. intestinalis, which is calling for further taxonomic investigation. More importantly, and unexpectedly, we also observed a genomic hotspot of long introgressed C. robusta tracts into C. intestinalis genomes at several locations of their contact zone. Both the genomic architecture of introgression, restricted to a 1.5 Mb region of chromosome 5, and its absence in allopatric populations suggest introgression is recent and occurred after the introduction of the non-indigenous species. Overall, our study shows that anthropogenic hybridization can be effective in promoting introgression breakthroughs between species at a late stage of the speciation continuum.

scholarly journals Are they always bad? Assessing benefits of non-indigenous species in aquatic environment and their implications

2020 ◽  
Vol 45 (2) ◽  
pp. 75-86
Author(s):  
Muhammad Masrur Islami
Keyword(s):  
Public Awareness ◽  
Natural Habitat ◽  
Ecological Change ◽  
Indigenous Species ◽  
Native Communities ◽  
Vector Management ◽  
Effective Policy ◽  
Management Approaches ◽  
Non Indigenous Species ◽  
And Control

Non-indigenous species (NIS), non-native, or alien species are any organisms living and spreading outside their natural habitat. Many of NIS spread to a new environment accidentally, while some other species are intentionally introduced by humans to a new habitat in many different pathways, as follows: 1) release; 2) escape; 3) contaminant; 4) stowaway; 5) corridor; and 6) unaided. Threaten native biodiversity may be the most problematic impact of NIS. They can also disrupt food-web organizations and affect the ecosystem structures. Additionally, the problem is exacerbated by disagreements regarding whether or not NIS should be permitted for aquaculture production. The likelihood of NIS escaping, being released from aquaculture, and establishing in its native habitat poses a significant threat to the ecosystem and biodiversity. NIS also have positive impacts as ecosystem engineers which may increase the biodiversity of native communities. Other benefits of NIS include providing an alternative food source and supporting fisheries and aquaculture sectors. Understanding the introduction process and the impacts of NIS should be supported by effective policy frameworks and management approaches, including risk assessment, prevention and control, pathway and vector management, early detection and rapid response, eradication, and mitigation and restoration. Furthermore, the crucial efforts would be raising public awareness, improving scientific research, and developing strategy regarding biosecurity issues as consequences of the emergence of interactions complexity among NIS and other global ecological change drivers.

Meta-analysis on the ecological impacts of widely spread non-indigenous species in the Baltic Sea

2021 ◽  
pp. 147375
Author(s):  
Henn Ojaveer ◽  
Jonne Kotta ◽  
Okko Outinen ◽  
Heli Einberg ◽  
Anastasija Zaiko ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Meta Analysis ◽  
Ecological Impacts ◽  
Indigenous Species ◽  
The Baltic Sea ◽  
The Baltic ◽  
Non Indigenous Species

scholarly journals First Record of the Alien Species Procambarus virginalis Lyko, 2017 in Fresh Waters of Sardinia and Insight into Its Genetic Variability

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 606
Author(s):  
Daria Sanna ◽  
Ilenia Azzena ◽  
Fabio Scarpa ◽  
Piero Cossu ◽  
Angela Pira ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Alien Species ◽  
Procambarus Clarkii ◽  
Mitochondrial Gene ◽  
First Record ◽  
Indigenous Species ◽  
Fresh Waters ◽  
Mediterranean Island ◽  
Marbled Crayfish ◽  
Non Indigenous Species

In the fresh waters of Sardinia (Italy), the non-indigenous crayfish species Procambarus clarkii has been reported from 2005, but, starting from 2019, there have been several reports of a new non-indigenous crayfish in southern and central areas of this Mediterranean island, and its morphology suggests that this species may be the marbled crayfish Procambarus virginalis. Forty-seven individuals of this putative species were analyzed, using the mitochondrial gene Cytochrome c Oxidase subunit I as molecular marker to identify this crayfish and investigate the level of genetic variability within the recently established population. Phylogenetic and phylogeographic analyses were carried out on a dataset including sequences from the Sardinian individuals and from all congenerics available in GenBank. Results showed that the new Sardinian crayfish belong to the species P. virginalis. All the sequences belonging to P. virginalis from European countries are identical, with only few exceptions found among Sardinian individuals. In conclusion, this paper highlights the occurrence of a new further alien species in the Sardinian fresh waters, which are already characterized by the high presence of non-indigenous species.

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