scholarly journals Survey of Presence of Non-Indigenous Eurytemora Carolleeae in the Gulf of Riga (Baltic Sea) Five Years After its First Discovery

2018 ◽  
Vol 72 (4) ◽  
pp. 230-235
Author(s):  
Labuce Astra ◽  
Ikauniece Anda ◽  
Strāķe Solvita ◽  
Souissi Anissa
Keyword(s):  
Baltic Sea ◽  
Calanoid Copepod ◽  
Reproduction Rate ◽  
Indigenous Species ◽  
Physiological Plasticity ◽  
Eurytemora Affinis ◽  
Male And Female ◽  
Key Species ◽  
Gulf Of Riga ◽  
Non Indigenous Species

Abstract In the brackish ecosystem of the Gulf of Riga, the calanoid copepod Eurytemora affinis is a key species, but recently a new non-indigenous species Eurytemora carolleeae was discovered in the region. In the present study, we aimed to validate the presence of E. carolleeae in the southern part of the Gulf of Riga five years after its first discovery. The study area is the closest region to the Rīga harbour — the main source of non-indigenous species arrival in the Gulf. Recent studies have predicted the possible potential of E. carolleeae invasion due to its physiological plasticity. Male and female specimens of Eurytemora were collected in spring, summer, and autumn of 2013, and analysed based on three morphological indicators. Despite the higher reproduction rate of E. carolleeae, this intrusive species does not seem to have succeeded in establishing during the five-year period after its first discovery in the Gulf of Riga, and hence does not present a threat to the native E. affinis population in the study area.

Taxon-specific prey response to the invasion of a pelagic invertebrate predator, revealed by comparison of pre- and post-invasion time series

2020 ◽  
Author(s):  
Heli Einberg ◽  
Riina Klais-Peets ◽  
Arno Põllumäe ◽  
Henn Ojaveer
Keyword(s):  
Time Series ◽  
Baltic Sea ◽  
Seasonal Abundance ◽  
Indigenous Species ◽  
Long Term Effects ◽  
Gulf Of Riga ◽  
Marine Realm ◽  
The Baltic ◽  
Non Indigenous Species

Abstract Quantification and attribution of the food web changes associated with the invasion of non-indigenous species in the marine realm often remain a challenge. One of the pelagic non-indigenous species of concern in the recent history of aquatic bioinvasions is the predatory cladoceran Cercopagis pengoi, which invaded the Baltic Sea in the early 1990s. While several studies have reported immediate declines in abundances of its potential prey, the long-term effects of C. pengoi on the food webs remain to be examined. Based on the long-term time series (1968–2018) in the Gulf of Riga (Baltic Sea), we found significant declines in abundance of the cladoceran Pleopis spp. and copepod Eurytemora affinis by 90 and 80%, respectively, are associated with the invasion of C. pengoi as well as significant alterations in seasonal abundance patterns of Pleopis spp., E. affinis and cladoceran Bosmina spp. The invasion of the non-indigenous predator has led to the changed prey abundance–temperature relationships. Special caution was taken in data preprocessing, to minimize the likelihood that observed changes in the zooplankton prey could be associated with factors other than the invasion of C. pengoi, such as temperature and storminess.

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 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.

Eurytemora affinis (Poppe, 1880) (Copepoda, Calanoida) in the Gulf of Riga, Baltic Sea — elemental composition and diurnal vertical migration

Crustaceana ◽  
2020 ◽  
Vol 93 (3-5) ◽  
pp. 447-466
Author(s):  
Astra Labuce ◽  
Solvita Strake ◽  
Inta Dimante-Deimantovica
Keyword(s):  
Surface Layer ◽  
Baltic Sea ◽  
Elemental Composition ◽  
Vertical Migration ◽  
Clupea Harengus ◽  
Elemental Content ◽  
Eurytemora Affinis ◽  
Diurnal Vertical Migration ◽  
Trade Offs ◽  
Gulf Of Riga

Abstract The present paper reports the results of two surveys conducted in the Gulf of Riga (Baltic Sea) during 1997. Elemental composition (carbon and nitrogen) and diurnal vertical migration (DVM) throughout development of the calanoid copepod Eurytemora affinis (Poppe, 1880) were studied. This is a species with a high genetic and morphological heterogeneity, inhabiting a seasonally stratified, herring (Clupea harengus Linnaeus, 1758) rich ecosystem. The DVM of copepods is a widespread advantageous behaviour, although with several trade-offs. At the expense of time spent in the food-richer surface layer, copepods avoid visual predators (planktivorous fish) by descending to greater depths, thereby decreasing their mortality. Being a part of the food web, copepods themselves serve as a source of nutrients with specific elemental contents. In the present study, we observed differences both in DVM and elemental content between the developmental stages of the studied species. The majority (57-89%) of nauplii and 1st to 3rd copepodids were found near the thermocline during daytime, whereas at night they were detected above the thermocline. The 5th stage copepodids and adults displayed evident nocturnal ascent, when most (>90%) individuals moved above 15 m depth. During daytime, they tended to disperse throughout the water column. Carbon (C%) and nitrogen (N%) in dry weight of E. affinis increased with ontogenetic development, reaching the highest values in 4th to 5th copepodids and adults. Adult males showed higher values of C% and N%, as well as an increased C : N molar ratio, compared to adult non-ovigerous females. The amount of time spent at the food-richer surface layer appeared to be related to N% in E. affinis.

scholarly journals The role of marinas in the establishment and spread of non-indigenous species in Baltic Sea fouling communities

Biofouling ◽  
2021 ◽  
pp. 1-14
Author(s):  
Okko Outinen ◽  
Riikka Puntila-Dodd ◽  
Ieva Barda ◽  
Radosław Brzana ◽  
Joanna Hegele-Drywa ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Indigenous Species ◽  
Fouling Communities ◽  
Non Indigenous Species

Distribution and abundance of Talitridae in the southern Baltic Sea – twelve years after the first record of Platorchestia platensis (Krøyer, 1845) in 2005

2019 ◽  
Vol 48 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Marta B. Tykarska ◽  
Urszula Janas ◽  
Radosław Brzana
Keyword(s):  
Baltic Sea ◽  
First Record ◽  
Indigenous Species ◽  
Gulf Of Gdańsk ◽  
Southern Baltic Sea ◽  
Open Sea ◽  
Talitrus Saltator ◽  
Southern Baltic ◽  
Non Indigenous Species ◽  
First Time

Abstract Four Talitridae species have been recorded in the southern Baltic Sea, including two indigenous species – Talitrus saltator, Deshayesorchestia deshayesii, and two presumably non-indigenous ones – Cryptorchestia garbinii, Platorchestia platensis. It has been twelve years since Platorchestia platensis was recorded for the first time. The distribution and abundance of talitrids have not been studied since the 1990s. Therefore, the main objective of this research was to document the occurrence in Talitridae in the region in order to determine whether non-indigenous P. platensis has spread and whether it co-occurs with indigenous species. Talitrids were recorded at 20 out of 43 sampling sites. T. saltator occurred both along the coast of the open sea and in the Gulf of Gdańsk. The remaining species were found only around the gulf. P. platensis was more abundant than other species and its density was positively correlated with wrack biomass. Our studies have shown that the area of T. saltator occurrence has decreased during the last two decades. Non-indigenous species P. platensis co-occurred with all other Talitridae species, whereas C. garbinii co-occurred only with P. platensis.

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