Plankton species

Losses of crustaceans, crayfish, mayflies, and some algal and zooplankton species occur as the pH approaches 6, but most fish are largely unaffected. In the range from pH 6 to 5, major population losses are experienced. Major changes of plankton species happen while progressive loss of fish species is hkely. Fish decline is often reflected in a failure of the species to reproduce... 

In contrast to their rather low dissolved concentrations in seawater, some of the trace metals, e g., iron and aluminum, along with oxygen and silicon, comprise the bulk of Earth s crust. Some trace elements are micronutrients and, hence, have the potential to control plankton species composition and productivity. This provides a connection in the crustal-ocean-atmosphere fectory to the carbon cycle and global climate. 

Changes in climate and meridional overturning circulation are likely to affect plankton species distributions. As discussed in Chapter 25.5.3, such changes have the potential to alter the biological carbon pumps. The associated feedbacks are also likely to be affected due to synergistic interactions with other pollution problems including nutrient loading. 

It is likely that cyanobactria synthesize poisons to ward off attack by other planktonic species. Carmichael etal. have found that cyanobacterial neurotoxins and hepatotoxins can be extremely harmful to the zooplankton living in the marine environment. This is a good example of the natural task of the toxins in protecting the organism that produces them. ... 

Except for sanguineum, the above named species represent cosmopolitan and frequently dominant epiphytic/benthic dinoflagel-lates in the Virgin Islands. Gymnodinium sanguineum is one of the few common planktonic species in the study area. All of these species are readily accessible to herbivorous fishes throughout the Virgin Island chain. 

Signature Signature is a term used by marine flow cytometrists to refer to the flow cytometric characteristics of particular planktonic species in a sample of water. The signature of plankton is related, in particular, to the autofluorescent pigments that are present. Signature has also been used to describe the distin-... 

In the periods of salination of the Sea of Azov, the invasion of a group of planktonic species from the Black Sea occurred [22],... 

Microscopy is a standard method for quantifying planktonic particulates. Counting by microscopy results in data, consisting of number concentrations of plankton species or other particulates, but it does not produce size distribution data. However, this method is direct and produces same information on particle shape, number, and type, which cannot be obtained by other means. 

Most sediment toxicity tests have been conducted in the laboratory with single species of freshwater and marine benthic organisms such as amphipods and midges, but in some cases planktonic species also have been used. Most tests conducted to date have been acute and have been of 10 days duration or less. Sediment toxicity tests are conducted with the solid phase or the pore water (interstitial water). Methods have been published describing the collection and preparation techniques. 

The availability of reliable test methods for contaminated sediments is relatively recent and the test method development process continues. A variety of issues remain to be solved before these types of studies will be considered as effective as those with planktonic species. Among the more important of these issues are validation of the single-species test results and determination of variations in species sensitivity. 

This temperature calibration (Fig. 5.44) is derived from a range of culture experiments, sediment-trap data and sedimentary cores calibrated against 5180 values for planktonic species of the foraminiferan Globigerina (Prahl Wakeham 1987 Prahl et al. 1988). The U37 parameter can be measured to an accuracy of 0.02 units, potentially allowing temperature to be determined to within 0.5 °C. 

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