68 



Samples are taken with a 0.25 m 2 Hessler-Sandia box core. The box core is fitted with 25 subcores so that 

 synoptic measurement can be made for biological (macrofauna and meiofauna), chemical (trace metals, 

 particularly barium, hydrocarbons), and sedimentological (grain size, TOC, carbonate, shear stress) properties. 



The central California shelf is rich in meiofauna. Meiofaunal continental shelf densities around the world span 

 two orders of magnitude with the Pacific being among the highest and the Gulf of Mexico being among the 

 lowest (Table 7). In the USA, the west coast has higher densities than the east coast. The east coast estimates 

 are remarkably similar to one another. Arctic and North Sea densities are as high as east Pacific densities. But, 

 the eastern Atlantic off Africa is also low. The southeastern Texas shelf of the Gulf of Mexico is very 

 depauperate in meiofauna. 



Table 7. Continental shelf meiofauna densities. 



Location 



Density 

 ltf/n/ 



Depth 

 m 



Author 



Montagna 1990 

 Montagna 1990 

 Tietjen 1971 

 Coull et al. 1982 

 Coull et al. 1977 

 Wigley & Mclntyre 1964 

 Mclntyre 1964 

 Faubel et al. 1983 

 Thiel 1975 



Pfannkuche & Thiel 1987 

 Pfannkuche & Thiel 1987 

 Thiel 1978 



Pequegnat & Sikora 1979 

 Pequegnat & Sikora 1979 



The most interesting outcome to date in the CAMP program is that macrofauna and meiofauna densities exhibit 

 little correlation with one another (Hyland 1988). Whereas, macrofauna densities decrease with increasing depth, 

 meiofauna do not. Also, macrofauna diversity decreases with depth, but meiofauna diversity increases with depth. 

 Both macrofauna and meiofauna exhibit some temporal trend but it is not seasonal. This indicates that 

 meiofauna and macrofauna probably have different roles in benthic shelf ecosystems. We know this to be true 

 in shallow water ecosystems (Coull and Bell 1979; Coull and Palmer 1984). Meiofauna, because of their small 

 size and shorter generation times, can have similar or higher productivity values than macrofauna (Gerlach 1971, 

 1978). Meiofauna, because they share similar spatial scales to microbes, also play important role in nutrient 

 cycling (Gerlach 1978). The CAMP study demonstrates the importance of studying both meiofauna and 

 macrofauna because they probably indicate different kinds of effects on the benthic ecosystem. 



Given the obviously low densities of meiofauna in the Gulf of Mexico, it is imperative that we develop an 

 understanding of food limitations in benthic webs in the Gulf. This will require understanding the benthic 

 microbial food sources that support meiofauna and macrofauna populations. 



GEEP Workshop 



The GEEP workshop was convened to perform a practical inter-calibration study and evaluate techniques for 

 the assessment of pollution in the sea (Bayne et al. 1988). All levels of biological organization were studied from 

 the molecular to the community, and all biological components from bacteria to macrofauna were included. Both 

 mesocosm and field experiments were performed. In the GEEP mesocosm experiment Warwick et al. (1988) 



