Changing Plankton Communities Causes Effects And Consequences

Marine ecosystems are changing at an unprecedented rate. In addition to the direct effects of e.g. warming surface temperatures, the environmental changes also cause shifts in plankton communities. Plankton makes up the base of the marine food web and plays a pivotal role in global biogeochemical cycles. Any shifts in the plankton community composition could have drastic consequences for marine ecosystem functioning. This Research Topic focuses on causes, effects and consequences of such shifts in the plankton community structure.

The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification.

In the marine environment, single-celled, microscopic, plant-like organisms naturally occur in the well-lit surface layer of any body of water. These organisms, referred to as phytoplankton or microalgae, form the base of the food web upon which nearly all other marine organisms depend. Algal bloom is a rapid increase in or accumulation of the population of about 300 species of algae due to excess nutrients (eutrophication), and is of major global interest as it causes reduction in species diversity, abrupt changes in water quality, and discoloration of the water (green, yellow, brown or red) depending on the species of algae and the type of pigments they contain. Dying blooms can also be an environmental concern as when the cells sink and decay, bacteria break down the organic material, which in turn strips oxygen from the water. This microbial oxygen demand at times leads to very low oxygen levels in the bottom waters, harming aquatic life. Documentation of this sporadic high abundance of algae, together with the significant species richness of the diatoms, requires comprehensive studies in the Sundarban coastal environment, which is facing severe degradation due to natural & anthropogenic stressors. In addition, a better understanding of the effects of algal blooms on seafood quality, the complex biological, chemical and physical interactions and subsequent effects on trophodynamics is needed to develop strategies for effective coastal zone management. The book discusses the occurrence of harmful algal blooms (HABs) caused by the dinoflagellates of the genus Alexandrium and Karenia, or diatoms of the genus Pseudo-nitzschia, which have large and varied impacts on marine ecosystems (such as large-scale marine mortality events that have been associated with various types of shellfish poisonings) depending on the species involved, the environment where they are found, and the mechanism by which they exert negative effects. HABs represent a major environmental problem in all regions of the U.S., and their occurrence is on the rise due to increased nutrient pollution. HABs have severe impacts on human health, aquatic ecosystems, and the economy. Such blooms, known colloquially as red tides due to their red or brown hues, are increasing in frequency and magnitude worldwide as a result of changes in oceanic climate, increased coastal eutrophication and enhanced long-distance dispersal in ballast water. As such, the book offers an in-depth account of the complex biological, chemical and physical interactions of the algal blooms (both innocuous and harmful ones). It also discusses the highly topical issue of the impact of global climate change on the frequency and severity of HABs in the context of alterations in temperature, stratification, light and ocean acidification. Focusing on both basic and applied limnology, this book is a reliable and up-to-date reference resource for students, teachers and researchers engaged in the field of coastal research/management at regional and global scales.

This book integrates a variety of issues such as regional settings of productivity and nutrient cycling; plankton of coastal and shelf systems; plankton, climate change and human-induced changes; harmful algae and their impacts; and gelatinous zooplankton. This book explores the intriguing marine plankton communities of the SWA region of South America encompassing low to high latitude environments, framed by a complex hydrographic background and global climate change. This vast and iconic region has been largely under-recognized and under-studied. However, in recent years a strong interest has emerged along with the acknowledgment of its high biological productivity. The book concludes by discussing conservation in the region, highlighting regional biodiversity hotspots where the challenges of climate change, habitat loss, and other threats to biodiversity may be particularly acute. Plankton Ecology of the Southwestern Atlantic is a timely synthesis of the field, setting a new baseline for future research. It will be important reading for both researchers and graduate students, and will also be of interest and use to a professional audience of oceanographers, conservation biologists, stake holders and educated science enthusiasts

Wetlands and grassland are important components of natural ecosystems, which have rich values in maintaining ecological balance, regional economy and human development. Wetlands can provide freshwater resources and food sources for human beings, purify the water environment and mitigate climate change. The grassland ecosystem has such ecological functions as windbreak, sand fixation, soil preservation, climate regulation, air purification, water conservation and so on, which are closely related to human survival and well-being. In recent years, climate change and human activities have caused a profound impact on the structure and function of wetland and grassland ecosystems, and the problems of decline in size and function have attracted extensive attention from researchers globally. However, there are still many uncertainties about the variety of wetland and grassland ecosystem composition, structure and dynamics, as well as how they respond and adapt to climate change and human activities.

The majority of global seafood production and mariculture activities take place in marine coastal water bodies, especially in areas of high primary productivity (from microalgae and plankton). This productivity sustains many forms of ecosystem services and promotes carbon dioxide absorption. However, climate change (ocean warming, acidification, oxygen loss, etc.) and anthropogenic disturbances (nutrients intrusion, aquaculture) have influenced the microalgae/plankton community assemblage and shifted it into a highly productive zone, causing a severe impact on the marine ecosystem, such as an increase in Harmful Algal Blooms, dead zone expansions, and coral-algal phase shifts. So far, there is still little knowledge on the mechanisms of microalgae/plankton community response to these changing environmental conditions. Harmful microalgae impair the marine ecosystem through the production of the so-called shellfish toxins, which cause shellfish contamination and poisoning to the vertebrates, including humans. In addition, some microalgae produce fish-killing toxins (ichthyotoxins), causing increasing damage to marine aquaculture. Besides that, the high productivity/bloom of microalgae in the water due to coastal eutrophication from anthropogenic activities is known to induce hypoxic-anoxic conditions causing a severe economic impact on aquaculture.

A richly illustrated guide to the marvelously diverse plankton of the world and their fundamental role in planetary food webs Plankton are the unsung heroes of planet Earth. Passive drifters through the world’s seas, oceans, and freshwater environments, most are invisible or very small, but some are longer than a whale. They are the global ocean’s foundation food, supporting almost all oceanic life, and they are also vitally important for land-based plants, animals, and other organisms. Plankton provides an incomparable look at these remarkable creatures, opening a window on the elegance and grace of microscopic marine life. This engaging book reveals the amazing diversity of plankton, how they belong to a wide range of living groups, and how their ecology, lifestyles, and adaptations have evolved to suit an enormous range of conditions. It looks at plankton life cycles, the different ways plankton feed and grow, and the vast range of strategies they use for reproduction. It tracks where, how, and why plankton drift through the water; shares perspectives on migrations and population explosions or “blooms” and why they happen; and discusses the life-sustaining role of plankton in numerous intertwined food webs throughout the world. Beautifully illustrated, Plankton sheds critical light on how global warming, pollution, diminishing resources, and overexploitation will adversely impact planktonic life, and how these effects will reverberate to every corner of our planet.