Environmental Impacts—Marine Ecosystems

Abstract

This chapter presents a review of what is known about the impacts of climate change on the biota (plankton, benthos, fish, seabirds and marine mammals) of the North Sea. Examples show how the changing North Sea environment is affecting biological processes and organisation at all scales, including the physiology, reproduction, growth, survival, behaviour and transport of individuals; the distribution, dynamics and evolution of populations; and the trophic structure and coupling of ecosystems. These complex responses can be detected because there are detailed long-term biological and environmental records for the North Sea; written records go back 500 years and archaeological records many thousands of years. The information presented here shows that the composition and productivity of the North Sea marine ecosystem is clearly affected by climate change and that this will have consequences for sustainable levels of harvesting and other ecosystem services in the future. Multi-variate ocean climate indicators that can be used to monitor and warn of changes in composition and productivity are now being developed for the North Sea.

Climate change not to blame for cod population decline

“…These are not the warmest areas in which cod occur 5 ; there are small stocks west of the British Isles where annual mean temperatures are up to 2 ºC higher ( Figure 2). Archaeological evidence that cod stocks persist at higher temperatures has been found in Mesolithic Stone Age Danish kitchen middens from a period (7000-3900 BC) when temperatures in that area were 2-2.5 ºC higher than the present 6 . The middens contained a high proportion of cod.…”

“…Fish experience a complex pattern of seasonal and geographical temperature variability, influenced by their vertical and horizontal migratory behaviour. Cod can rapidly change their depth and hence ambient temperature 6 . Processes such as cod growth are nonlinear with respect to temperature and to fish size, so that growth at the same annual mean temperature will be different depending on whether the seasonal temperature variability is large or small or whether the fish are large or small 6 .…”

“…Cod can rapidly change their depth and hence ambient temperature 6 . Processes such as cod growth are nonlinear with respect to temperature and to fish size, so that growth at the same annual mean temperature will be different depending on whether the seasonal temperature variability is large or small or whether the fish are large or small 6 . Variation in annual mean SST is inevitably a crude representation of this complex thermal history, but adequate for examining overall trends.…”

Plankton and benthos similarity indices as indicators of the impact of mangrove plantation on the environmental quality of silvofishery ponds

“…However, there must be matched environmental conditions to support both the plankton and the dependent organism in the food chain. Organisms and environment within an ecosystem will change over time in response to ecosystem disturbances and services (Brander et al 2016). In order to formulate appropriate aquaculture management plans, thorough consideration of potential change in the supporting ecosystems is required…”

Assessment of Changes in the Structure of Zooplankton Communities to Infer Water Quality of the Caspian Sea

“…Global warming, along with an increased anthropogenic load, is the main predictor of long-term changes in marine ecosystems [1][2][3]. The Caspian Sea, the largest inland water body, is polluted by precipitation, shipping traffic, oil operations, and emergency oil spills [4].…”