Assessing Marine Ecosystem Health: The Long-Term Effects of Fishing on Functional Biodiversity in North Sea Benthos

2003 ◽  
Vol 6 (2) ◽  
pp. 131-137 ◽  
Author(s):  
J. Bremner ◽  
C. L. J. Frid ◽  
S. I. Rogers
2006 ◽  
Vol 113 (1-3) ◽  
pp. 31-48 ◽  
Author(s):  
Mark L. Mallory ◽  
H. Grant Gilchrist ◽  
Birgit M. Braune ◽  
Anthony J. Gaston

2018 ◽  
Author(s):  
Andrea A. Cabrera ◽  
Elena Schall ◽  
Martine Bérubé ◽  
Lutz Bachmann ◽  
Simon Berrow ◽  
...  

AbstractThe demography of baleen whales and their prey during the past 30 thousand years was assessed to understand the effects of past rapid global warming on marine ecosystems. Mitochondrial and genome-wide DNA sequence variation in eight baleen whale and seven prey species revealed strong, ocean-wide demographic changes that were correlated with changes in global temperatures and regional oceanographic conditions. In the Southern Ocean baleen whale and prey abundance increased exponentially and in apparent synchrony, whereas changes in abundance varied among species in the more heterogeneous North Atlantic Ocean. The estimated changes in whale abundance correlated with increases in the abundance of prey likely driven by reductions in sea-ice cover and an overall increase in primary production. However, the specific regional oceanographic environment, trophic interactions and species ecology also appeared to play an important role. Somewhat surprisingly the abundance of baleen whales and prey continued to increase for several thousand years after global temperatures stabilized. These findings warn of the potential for dramatic, long-term effects of current climate changes on the marine ecosystem.One Sentence SummaryThe effects of past global warming on marine ecosystems were drastic, system-wide and long-lasting.


2015 ◽  
Vol 528 ◽  
pp. 257-265 ◽  
Author(s):  
C Stenberg ◽  
JG Støttrup ◽  
M van Deurs ◽  
CW Berg ◽  
GE Dinesen ◽  
...  

2018 ◽  
Author(s):  
Amrit K Mishra

Rising carbon dioxide (CO2) concentrations in the atmosphere will increase the average pCO2 level in the world oceans, which will have a knock-on effect on the marine ecosystem. Coastal seagrass communities are predicted to benefit from the increase in CO2 levels, but long-term effects of elevated CO2 on seagrass communities are less understood. Population reconstruction techniques were used to investigate the population dynamics of Cymodocea nodosa meadows, exposed to long term elevated CO2 at volcanic seeps off Greece and Italy. Effect of elevated CO2 was noticed on the growth, morphometry, density, biomass and age structure at CO2 seeps than reference sites. Above to below ground biomass ratio of C. nodosa were higher at CO2 seeps. The shoot age and shoot longevity of plants were lower at seeps. The present recruitment (sampled year) of the seagrass were higher than long-term average recruitment of the communities near the seeps. Carbon to nitrogen ratios (%DW) and annual leaf production of C. nodosa were higher in leaves at seeps. This study suggests under long-term CO2 enrichment C. nodosa production increases, but the plant survival rate decreases because of other co-factors such as nutrient availability and trace metal toxicity. Therefore, along with high CO2 other factors must be taken into consideration while predicting effects of future CO2 concentrations.


2018 ◽  
Vol 76 (4) ◽  
pp. 925-937 ◽  
Author(s):  
Gabriella E Church ◽  
Robert W Furness ◽  
Glen Tyler ◽  
Lucy Gilbert ◽  
Stephen C Votier

Abstract Understanding anthropogenic impacts are crucial to maintain marine ecosystem health. The North Sea has changed in recent decades, largely due to commercial fishing and climate change. Seabirds can act as useful indicators of these changes. By analyzing n = 20 013 pellets and n = 24 993 otoliths regurgitated by great skuas Stercorarius skua in northern Scotland over five decades from the 1970s to the 2010s (in 36 years 1973–2017), we reveal how the diet of this top predator has changed alongside the changing North Sea ecosystem. Sandeels Ammodytes spp. were the most common dietary item during the 1970s, but became virtually absent from the 1980s onward. Discarded whitefish dominated skua diets from the 1980s to the present day, despite long-term declines in North Sea discard production. However, the discarded fish eaten by great skuas has become smaller and the species composition changed. Skua pellets only rarely contained avian prey in the 1970s but this increased during the 1980s, and fluctuated between 10% and 20% from the 1990s to 2010s. There have also been changes in the avian prey in the diet—black-legged kittiwakes Rissa tridactyla generally being replaced by auks Alcid spp. and northern fulmars Fulmarus glacialis. The Shetland marine ecosystem has experienced steep declines in sandeel stocks and in seabirds that feed on them. Great skuas have been able to prey switch to respond to this change, supported by abundant discards, enabling them to maintain a favourable population status while other seabird species have declined.


PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e77360 ◽  
Author(s):  
Rocío Moreno ◽  
Lluís Jover ◽  
Carmen Diez ◽  
Francesc Sardà ◽  
Carola Sanpera

2009 ◽  
Vol 82 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Morten D. Skogen ◽  
Lene R. Mathisen

2019 ◽  
Author(s):  
Elena Couce ◽  
Michaela Schratzberger ◽  
Georg H. Engelhard

Abstract. Fishing – especially trawling – is one of the most ubiquitous anthropogenic pressures on marine ecosystems worldwide, yet very few long-term, spatially explicit datasets on trawling effort exist; this greatly hampers our understanding of the medium- to long-term impact of trawling. This important gap is addressed here for the North Sea, a highly productive shelf sea which is also subject to many anthropogenic pressures. For a 31-year time span (1985–2015), we provide a dataset on the spatial distribution of total international otter and beam trawling effort, for all ICES rectangles (0.5° latitude by 1° longitude) of the North Sea. The dataset was largely reconstructed using compiled effort data from 7 fishing effort time-series, each covering shorter time spans and some of the countries fishing the North Sea only. For the years where effort data for particular countries were missing, the series was complemented using estimated (modelled) effort data. This new, long-term and large-scale trawling dataset may serve the wider scientific community, as well as those involved with policy and management, as a valuable information source on fishing pressure in a Large Marine Ecosystem which is heavily impacted, but which simultaneously provides a wealth of ecosystem services to society. The dataset is available on the Cefas Data Hub at: https://doi.org/10.14466/CefasDataHub.61 (Couce et al., 2019).


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