Benthos

Days to seasonal in small benthos annual to multi-annual in large benthos... 

From the large body of literature about chemical defense in the benthic environment (benthos the bottom of the sea and the littoral zones), only a few aspects can be highlighted here. The selection of examples from the benthos will focus on dynamic defense reactions including fast wound-activated and... 

Horowitz, A. and B J. Presley. 1977. Trace metal concentrations and partitioning in zooplankton, neuston, and benthos from the south Texas Outer Continental Shelf. Arch. Environ. Contam. Toxicol. 5 241-255. 

Neff, J.M., R.S. Foster, and J.F. Slowey. 1978. Availability of sediment-absorbed heavy metals to benthos with particular emphasis on deposit-feeding infauna. Tech. Rep. D-78-42, U.S. Army Waterways Exp. Sta., Vicksburg, MS. 286 pp. 

Weis, J.S. and P. Weis. 1994. Effects of contaminants from chromated copper arsenate-treated lumber on benthos. Arch. Environ. Contam. Toxicol. 26 103-109. 

Some populations of freshwater isopods are tolerant to lead. Inasmuch as nontolerant isopods from an unpolluted site can be made tolerant by exposure to low levels, it is suggested that naturally occurring tolerance may be achieved by acclimatization (Fraser 1980). Research is needed on lead transformation mechanisms, on toxic forms of lead and interaction effects with other compounds, and on effects of lead-contaminated sediments on benthos (Wong et al. 1978). 

Hay ME, Fenical W (1992) Chemical mediation of seaweed-herbivore interactions. In John DM, Hawkins SS, Price JH (eds) Plant-animal interactions in the marine benthos. Systematics Association Special Volume I. Clarendon, Oxford, pp 319-337 Hay ME, Fenical W (1996) Chemical ecology and marine biodiversity insights and products from the sea. Oceanography 9 10-20... 

Brand TE (1980) Trophic interactions and community ecology of the shallow-water marine benthos along the Antarctic Peninsula. PhD Dissertation, University of California Davis Cormaci M, Fumari G, Scammacca B (1992) The benthic algal flora of Terra Nova Bay (Ross Sea, Antarctica). Bot Mar 35 541-552... 

Significant concentrations of cyanotoxins have been found to accumulate in the tissues of macroinvertebrates such as mollusks and crustaceans, presenting an indirect route of exposure for invertebrates, fish, and aquatic mammals at higher trophic levels (Negri and Jones 1995). In natural systems, mortality among benthic invertebrate herbivores is probably low because most bloom-forming bacteria are planktonic and only periodically come into contact with the benthos. Nevertheless, Kotak et al. (1996) determined that enhanced mortality of snails at the end of a bloom cycle in Canadian lakes was due to consumption of Microcystis cells that had formed a scum on the surface of macrophytes. Oberemm et al. (1999) found that aqueous microcystins, saxitoxins, and anatoxin-a all resulted in developmental delays in fish and salamander embryos. Interestingly, more severe malformations and enhanced mortality were observed when larvae were exposed to crude cyanobacterial extracts than to pure toxins applied at natural concentrations (Oberemm et al. 1999). 

Kitahara et al. decided on a classical approach for generating the bentho-cyanin A skeleton [85]. Following Hollimann [86] they started their synthesis with the one-step preparation of the phenazine 106 by reaction of 100 and... 

Even as part of the sediments, POM is subject to respiration. The effects of the benthos are greatest at the sediment-water interfece, but remineralization due to respiration... 

Importance of the biological pump in supplying the benthos with POM. Source From Rullkotter, J. (2000). Marine Geochemistry, Springer Verlag, pp. 125-126. 

As described in Chapter 17.4, evaporites can contain biogenic detritus produced by the benthos. 

Where the waves and currents weaken, resuspended sediment settles back down to the seafloor. Given the small particle sizes of the suspended material (mostly 3 to 10 pm), redeposition can take many years. The resulting redistribution of sediments creates patches of clay, mud, and exposed rock on the continental margins. In other words, resuspension from waves and currents can cause some sediments to become reUct deposits. Hard bottoms can serve as good habitats for some members of the benthos as they promote the formation of coral reefs. For paleoceanographers, relict deposits are problematic because they represent gaps, or imconformities, in the sedimentary record. 

On average about 20% of the BSi arriving at the sediment-water interfece dissolves prior to burial. Thus, only 3 to 5% of the surface production survives to become buried in the sediments. At some locations, where the BSi rain rate is high, a larger percentage (around 30%) is preserved. In comparison, 90% of the POC that rains onto the sediments is remineralized by the benthos, leaving sediment concentrations on the order of 1% w/w organic carbon. 

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