scholarly journals Male Antarctic fur seals: neglected food competitors of bioindicator species in the context of an increasing Antarctic krill fishery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. D. Lowther ◽  
I. Staniland ◽  
C. Lydersen ◽  
K. M. Kovacs
Keyword(s):  
Antarctic Krill ◽  
Marine Protected Area ◽  
Monitoring Program ◽  
Fishing Effort ◽  
Bioindicator Species ◽  
Ecosystem Monitoring ◽  
Holistic View ◽  
Fur Seals ◽  
Antarctic Fur Seals

Abstract The fishery for Antarctic krill is currently managed using a precautionary, ecosystem-based approach to limiting catch, with performance indices from a long-term monitoring program focused on several krill-dependent predators that are used to track ecosystem health. Concerns over increased fishing in concentrated areas and ongoing efforts to establish a Marine Protected Area along the Peninsula, a key fishing region, is driving the development of an adaptive management system for the fishery. The cumulative effects of fishing effort and interactions among krill-dependent predators and their performance is at present neglected in the CCAMLR Ecosystem Monitoring Program. However, we show considerable overlap between male Antarctic fur seals and the krill fishery in a complex mosaic, suggesting potential for cumulative impacts on other krill dependent predators. A holistic view is required as part of future efforts to manage the krill fishery that incorporates various sources of potential impacts on the performance of bioindicator species, including the fishery and its interactions with various krill dependent predators.

scholarly journals Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada

2021 ◽  
Vol 16 (12) ◽  
pp. 124024
Author(s):  
Lauren A MacDonald ◽  
Kevin W Turner ◽  
Ian McDonald ◽  
Mitchell L Kay ◽  
Roland I Hall ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Monitoring Program ◽  
Additive Models ◽  
Water Levels ◽  
Wildlife Habitat ◽  
Ecosystem Monitoring ◽  
International Polar Year ◽  
Monitoring Programs ◽  
Old Crow Flats

Abstract Lake-rich northern permafrost landscapes are sensitive to changing climate conditions, but ability to track real-time and potentially multiple hydrological responses (e.g. lake expansion, drawdown, drainage) is challenging due to absence of long-term, sustainable monitoring programs in these remote locations. Old Crow Flats (OCF), Yukon, is a Ramsar Wetland of International Importance where concerns about low water levels and their consequences for wildlife habitat and traditional ways of life prompted multidisciplinary studies during the International Polar Year (2007–2008) and led to the establishment of an aquatic ecosystem monitoring program. Here, we report water isotope data from 14 representative thermokarst lakes in OCF, the foundation of the monitoring program, and time-series of derived metrics including the isotope composition of input waters and evaporation-to-inflow ratios for a 13 year period (2007–2019). Although the lakes spanned multiple hydrological categories (i.e. rainfall-, snowmelt- and evaporation-dominated) based on initial surveys, well-defined trends from application of generalized additive models and meteorological records reveal that lakes have become increasingly influenced by rainfall, and potentially waters from thawing permafrost. These sources of input have led to more positive lake water balances. Given the documented role of rainfall in causing thermokarst lake drainage events in OCF and elsewhere, we anticipate increased vulnerability of lateral water export from OCF. This study demonstrates the value of long-term isotope-based monitoring programs for identifying hydrological consequences of climate change in lake-rich permafrost landscapes.

Squid in the diet of Antarctic fur seals: potential links to oceanographic conditions and Antarctic krill abundance

2019 ◽  
Vol 628 ◽  
pp. 211-221 ◽  
Author(s):  
J Abreu ◽  
I Staniland ◽  
CF Rodrigues ◽  
JP Queirós ◽  
JM Pereira ◽  
...  
Keyword(s):  
Antarctic Krill ◽  
Krill Abundance ◽  
Fur Seals ◽  
Oceanographic Conditions ◽  
Antarctic Fur Seals

scholarly journals Winter distribution of juvenile and sub-adult male Antarctic fur seals (Arctocephalus gazella) along the western Antarctic Peninsula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David March ◽  
Massimiliano Drago ◽  
Manel Gazo ◽  
Mariluz Parga ◽  
Diego Rita ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Adult Male ◽  
Antarctic Krill ◽  
South Shetland Islands ◽  
Distribution Area ◽  
Arctocephalus Gazella ◽  
Western Antarctic Peninsula ◽  
Adult Males ◽  
Fur Seals ◽  
Antarctic Fur Seals

AbstractDetailed knowledge of habitat use by marine megafauna is critical to understand their ecological roles and for the adequate management of marine resources. Antarctic fur seals (Arctocephalus gazella) inhabiting the Atlantic sector of the Southern Ocean prey largely on Antarctic krill (Euphausia superba) and play a central role in managing the krill fishery. Here, we assessed the demographic structure of three post-mating, early moult male haul-outs in the South Shetland Islands in early March and calculated the relative contribution of juveniles (1–4 years old) and sub-adult males (5–6 years) to the population remaining in maritime Antarctica after the breeding season. We also satellite tagged 11 juvenile males and four sub-adult males to analyze their movements and develop a species distribution model including both age classes. Our results highlighted the dominance of young individuals in the male population, revealed that they do not behave as central place foragers and identified key environmental drivers that affected their distribution at-sea throughout winter. Predicted potential foraging habitat overlapped highly with the known distribution of Antarctic krill, and identified the waters off the western Antarctic Peninsula and the Scotia Sea as the core of the distribution area of juvenile and sub-adult male Antarctic fur seals in winter. This pattern is similar to that of adult males but totally different from that of adult females, as the latter overwinter in areas at latitude 45–55° S. This segregation has implications for the ecology and management of the krill fishery.

scholarly journals Wintertime overlaps between female Antarctic fur seals (Arctocephalus gazella) and the krill fishery at South Georgia, South Atlantic

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248071
Author(s):  
Connor C. G. Bamford ◽  
Victoria Warwick-Evans ◽  
Iain J. Staniland ◽  
Jennifer A. Jackson ◽  
Philip N. Trathan
Keyword(s):  
Antarctic Krill ◽  
Euphausia Superba ◽  
Arctocephalus Gazella ◽  
Habitat Models ◽  
South Georgia ◽  
Fur Seals ◽  
Fur Seal ◽  
Ice Edge ◽  
Future Work ◽  
Antarctic Fur Seals

The diet of Antarctic fur seals (Arctocephalus gazella) at South Georgia is dominated by Antarctic krill (Euphausia superba). During the breeding season, foraging trips by lactating female fur seals are constrained by their need to return to land to provision their pups. Post-breeding, seals disperse in order to feed and recover condition; estimates indicate c.70% of females remain near to South Georgia, whilst others head west towards the Patagonian Shelf or south to the ice-edge. The krill fishery at South Georgia operates only during the winter, providing the potential for fur seal: fishery interaction during these months. Here we use available winter (May to September) tracking data from Platform Terminal Transmitter (PTT) tags deployed on female fur seals at Bird Island, South Georgia. We develop habitat models describing their distribution during the winters of 1999 and 2003 with the aim of visualising and quantifying the degree of spatial overlap between female fur seals and krill harvesting in South Georgia waters. We show that spatial distribution of fur seals around South Georgia is extensive, and that the krill fishery overlaps with small, highly localised areas of available fur seal habitat. From these findings we discuss the implications for management, and future work.

scholarly journals Bringing citizen monitoring into land management: a case study of the Bosque Ecosystem Monitoring Program

2016 ◽  
Vol 15 (03) ◽  
pp. A02 ◽  
Author(s):  
Rowan Converse ◽  
Daniel Shaw ◽  
Kim Eichhorst ◽  
May Leinhart
Keyword(s):  
Natural Resource ◽  
Monitoring Program ◽  
Rapid Expansion ◽  
Federal State ◽  
Ecosystem Monitoring ◽  
Resource Managers ◽  
Natural Resource Managers ◽  
Citizen Monitoring

Despite the rapid expansion of citizen-based monitoring, data from these programs remain underutilized by natural resource managers, perhaps due to quality and comparability issues. We present the Bosque Ecosystem Monitoring Program as a case study of an initiative successfully meeting long-term monitoring needs of federal, state, tribal, and local natural resource managers, and informing public policy. To maximize potential for partnerships with managers, we recommend the creation of a five-year plan including scientific goals and financial solvency strategies prior to establishing a citizen science program, and offering multiple platforms for data-sharing and dialogue.

MODELING THE CONSEQUENCES OF ANTARCTIC KRILL HARVESTING ON ANTARCTIC FUR SEALS

2000 ◽  
Vol 10 (6) ◽  
pp. 1806-1819 ◽  
Author(s):  
R. B. Thomson ◽  
D. S. Butterworth ◽  
I. L. Boyd ◽  
J. P. Croxall
Keyword(s):  
Antarctic Krill ◽  
Fur Seals ◽  
Antarctic Fur Seals
Sign in / Sign up

Export Citation Format

Share Document