Satellite Telemetry Informs PCB Source Apportionment in a Mobile, High Trophic Level Marine Mammal: The Ringed Seal (Pusa hispida)

2014 ◽  
Vol 48 (22) ◽  
pp. 13110-13119 ◽  
Author(s):  
Tanya M. Brown ◽  
Sebastian Luque ◽  
Becky Sjare ◽  
Aaron T. Fisk ◽  
Caren C. Helbing ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Trophic Level ◽  
Marine Mammal ◽  
Satellite Telemetry ◽  
Ringed Seal ◽  
High Trophic Level ◽  
Pusa Hispida

scholarly journals Bacular and testicular growth and allometry in the ringed seal (Pusa hispida): evidence of polygyny?

2011 ◽  
Vol 92 (4) ◽  
pp. 803-810 ◽  
Author(s):  
David J. Yurkowski ◽  
Magaly Chambellant ◽  
Steven H. Ferguson
Keyword(s):  
Ringed Seal ◽  
Testicular Growth ◽  
Pusa Hispida

USE OF DISSOLVED ORGANIC MATTER BY MICROORGANISMS: FORMATION OF WATER QUALITY IN A POND OF A HIGH TROPHIC LEVEL

Fisheries ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 25-29
Author(s):  
Anatoliy Sadchikov ◽  
Sergey Ostroumov
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Trophic Level ◽  
Aquatic Ecosystem ◽  
High Trophic Level ◽  
Bacterioplankton Community ◽  
Algae And Bacteria

The role of algae and bacteria in the consumption and mineralization of dissolved organic matter (DOM) in a highly trophic aquatic ecosystem was studied. The phytoplankton and bacterioplankton community consumed 60% of added DOM in August and 56% of DOM in September. Of the uptaken DOM, a significant amount of organic carbon was mineralized. In August 42.7% and in September 29% of organic carbon (of the consumed organic matter) were used for respiration.

scholarly journals Ringed seal (Pusa hispida) diet on the west coast of Spitsbergen, Svalbard, Norway: during a time of ecosystem change

Polar Biology ◽  
2020 ◽  
Vol 43 (7) ◽  
pp. 773-788
Author(s):  
O. Bengtsson ◽  
C. Lydersen ◽  
K. M. Kovacs ◽  
U. Lindström
Keyword(s):  
West Coast ◽  
Ringed Seal ◽  
Ecosystem Change ◽  
The West ◽  
Pusa Hispida

Fishing through (and up) Alaskan food webs

2009 ◽  
Vol 66 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Michael A. Litzow ◽  
Daniel Urban
Keyword(s):  
Time Series ◽  
Trophic Level ◽  
High Trophic Level ◽  
Climate Index ◽  
Climate Regime ◽  
Fisheries Sustainability ◽  
Competing Hypotheses ◽  
Mean Trophic Level ◽  
Highly Correlated ◽  
Historical Periods

We used a 112-year time series of Alaskan fishery catches to test competing hypotheses concerning trends in mean catch trophic level, a widely used indicator of fisheries sustainability. We found that mean trophic level has generally remained steady or increased in recent decades on Alaska-wide and regional scales, indicating stable catches of high trophic level taxa. During historical periods of declining mean trophic level, catches of upper trophic level taxa either increased or remained steady, contrary to the predictions of the “fishing down the food web” hypothesis. Further, a climate index was highly correlated (r = 0.69–0.97) with mean trophic level and (or) the related fisheries in balance (FIB) index across climate regime shifts in the 1940s and 1970s, indicating that climate effects, particularly on high trophic level taxa, can act as the major driver of variability in these parameters. These results provide a contrast to the view of ubiquitous declines in mean trophic level of fishery catches, driven by overexploitation and serial stock replacement.

Fireproof killer whales (Orcinus orca): flame-retardant chemicals and the conservation imperative in the charismatic icon of British Columbia, Canada

2006 ◽  
Vol 63 (1) ◽  
pp. 224-234 ◽  
Author(s):  
Peter S Ross
Keyword(s):  
British Columbia ◽  
Trophic Level ◽  
Polybrominated Diphenyl Ethers ◽  
Marine Mammals ◽  
Polychlorinated Biphenyl ◽  
High Trophic Level ◽  
Orcinus Orca ◽  
Weight Of Evidence ◽  
Older Individuals ◽  
Killer Whales

Long-lived and high trophic level marine mammals are vulnerable to accumulating often very high concentrations of persistent chemicals, including pesticides, industrial by-products, and flame retardants. In the case of killer whales (Orcinus orca), some of the older individuals currently frequenting the coastal waters of British Columbia (BC) were born during the First World War, well before the advent of widespread chemical manufacture and use. BC's killer whales are now among the most polychlorinated biphenyl (PCB) contaminated marine mammals in the world. While the "legacy" PCBs have largely been banned, polybrominated diphenyl ethers (PBDEs) have recently emerged as a major concern. The endocrine-disrupting nature of these two persistent fire retardants in biota spells trouble at the top of the food chain, with increasing evidence of effects on reproductive health, the immune system, and development in exposed mammals. The heavy contamination of BC's killer whales, coupled with their long life span and high trophic level, highlights the need for a "weight of evidence" approach in research, conservation planning, and regulatory decisions. Given the global nature of contaminant dispersion, such approaches can only be effective when carried out on both national and international scales.

Historical changes in mean trophic level of southern Australian fisheries

2014 ◽  
Vol 65 (10) ◽  
pp. 884 ◽  
Author(s):  
Heidi K. Alleway ◽  
Sean D. Connell ◽  
Tim M. Ward ◽  
Bronwyn M. Gillanders
Keyword(s):  
Trophic Level ◽  
Spatial Data ◽  
South Australia ◽  
Trophic Levels ◽  
High Trophic Level ◽  
Fishing Pressure ◽  
Time Line ◽  
The Mean ◽  
Mean Trophic Level ◽  
Catch Statistics

Decreases in the mean trophic level (MTL) of fishery catches have been used to infer reductions in the abundance of high trophic level species caused by fishing pressure. Previous assessments of southern Australian fisheries have been inconclusive. The objectives of the present study were to provide more accurate estimates of MTL using disaggregated taxonomic and spatial data. We applied the model of MTL to fisheries catch statistics for the state of South Australia from 1951 to 2010 and a novel set of historical market data from 1936 to 1946. Results show that from 1951 to 2010, MTL declined by 0.16 of a trophic level per decade; a rate greater than the global average of 0.10 but equivalent to similar regional investigations in other areas. This change is mainly attributable to large increases in catches of sardine, rather than reductions in the catches of high trophic level species. The pattern is maintained when the historical data is included, providing a time line from 1936 to 2010. Our results show a broadening of the catch of lower trophic levels and suggest care in interpretation of MTL of catches because reductions do not necessarily reflect change in high trophic level species by fishing pressure.

High trophic level and low diversity: Would Madeira benefit from fishing down?

Marine Policy ◽  
2016 ◽  
Vol 73 ◽  
pp. 130-137 ◽  
Author(s):  
Margarida Hermida ◽  
João Delgado
Keyword(s):  
Trophic Level ◽  
High Trophic Level ◽  
Low Diversity
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