Journal ArticleDOI
Climate effects on formation of jellyfish and ctenophore blooms: a review
TLDR
In eleven species studied from subtropical, temperate and subarctic environments, warm temperatures were related to large population sizes; three scyphozoan species in the North Sea, and one mesopelagic hydromedusan were exceptions to that trend.Abstract:
Much speculation and some evidence suggest that jellyfish and ctenophore populations have increased in recent decades. Unfortunately, few past records exist with which to compare current populations, and our knowledge of how environmental factors affect jellyfish population size is meagre. Human enterprise has wrought many changes in the ocean that are hypothesized to favour jellyfish, including eutrophication, reduction of fish stocks, and global warming. In addition to anthropogenic changes, natural climate cycles may affect jellyfish populations. Records of jellyfish and ctenophore abundance that appear to be related to indices of climate variations (temperature, salinity, North Atlantic Oscillation, North Pacific Decadal Oscillation, El Nino Southern Oscillation) are reviewed. In eleven species studied from subtropical, temperate and subarctic environments, warm temperatures were related to large population sizes; three scyphozoan species in the North Sea, and one mesopelagic hydromedusan were exceptions to that trend. One tropical scyphomedusan species was decimated by unusually warm, salty El Nino conditions in Palau. Because climate changes have complex ecosystem-level effects, the proximate causes of jellyfish increases are difficult to deduce. Therefore, the effects of temperature, salinity and prey on asexual production of new medusae from the benthic polyps of scyphomedusae and hydromedusae also are reviewed. Experiments on temperate species show greater and more rapid production of medusae at warmer temperatures. Salinity also had significant effects, and was especially important for estuarine species. Temperature and salinity affect asexual reproduction rates directly through metabolism, and indirectly through prey capture. Ocean warming may shift the distributions, expand the seasonal occurrence, and increase the abundances of temperate-boreal species. Populations living near their thermal maximum may suffer negative consequences of warming.read more
Citations
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Journal ArticleDOI
Anthropogenic causes of jellyfish blooms and their direct consequences for humans: a review
TL;DR: In this article, the authors summarize cases of problem jellyfish blooms and the evidence for anthropogenic habitat disruptions that may have caused them, and conclude that human effects on coastal environments are certain to increase, and jellyfish bloom may increase as a consequence.
Journal ArticleDOI
In hot water: zooplankton and climate change
TL;DR: In this article, an overview of the observed and potential future responses of zooplankton communities to global warming is provided, including changes in the distribution of individual species and assemblages, in the timing of important life cycle events, and in abundance and community structure.
Journal ArticleDOI
Ocean acidification and its potential effects on marine ecosystems.
TL;DR: The risk of irreversible ecosystem changes due to ocean acidification should enlighten the ongoing CO2 emissions debate and make it clear that the human dependence on fossil fuels must end quickly.
Journal ArticleDOI
Jellyfish and Ctenophore Blooms Coincide with Human Proliferations and Environmental Perturbations
TL;DR: Evidence suggesting that human activities--specifically, seafood harvest, eutrophication, hard substrate additions, transport of nonindigenous species, aquaculture, and climate change--may benefit jelly populations is explored, which shows abundant jellies in areas with warm temperatures and low forage fish populations.
Journal ArticleDOI
Increasing jellyfish populations: trends in Large Marine Ecosystems
Lucas Brotz,William W. L. Cheung,William W. L. Cheung,Kristin M. Kleisner,E. A. Pakhomov,Daniel Pauly +5 more
TL;DR: Of the 66 LMEs defined thus far that cover the world’s coastal waters and seas, trends of jellyfish abundance after 1950 (increasing, decreasing, or stable/variable) were identified for 45, with variable degrees of confidence.
References
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Journal ArticleDOI
Warming of the World Ocean
TL;DR: In this article, the authors quantify the interannual-to-decadal variability of the heat content (mean temperature) of the world ocean from the surface through 3000-meter depth for the period 1948 to 1998, showing that the global volume mean temperature increase for the 0- to 300-meter layer was 0.31°C, corresponding to an increase in heat content for this layer of ∼10 23 joules between the mid-1950s and mid-1990s.
Journal ArticleDOI
Ecological effects of the North Atlantic Oscillation
TL;DR: It is proposed that theNAO effects may be classified as three types: direct, indirect and integrated, which will help the design and interpretation of analyses attempting to relate ecological changes to the NAO and, possibly, to climate in general.
Journal ArticleDOI
Synopsis of the Medusae of the world
TL;DR: This work was started many years ago in the form of a card-index for my own use, but later on it saved me time for my studies, and it was not difficult to keep it up to date.
Book ChapterDOI
Jellyfish blooms: are populations increasing globally in response to changing ocean conditions?
TL;DR: Over recent decades, man's expanding influence on the oceans has begun to cause real change and there is reason to think that in some regions, new blooms of jellyfish are occurring in response to some of the cumulative effects of these impacts.
Journal ArticleDOI
Community reorganization in the Gulf of Alaska following ocean climate regime shift
Paul J. Anderson,John F. Piatt +1 more
TL;DR: A shift in ocean climate during the late 1970s triggered a reorganization of community structure in the Gulf of Alaska ecosystem, as evidenced in changing catch composi- tion on long-term (1953-1997) small-mesh trawl surveys.