m@rble ELectronic conference on MARine Biodiversity in Europe

summaries theme 1

Summaries of theme 1, as they are posted here, are compiled by the session's chairman, Carlos Duarte.

main issues in marine biodiversity research

Summary of day 3

Please post your message to the relevant topic in forum.

I am aware that the discussion is leading to unexpected interlinks between different topics in the discussion forum. However, most comments seem to be directed to the first topic on the list, most likely because is the first to be encountered, whereas many of these do really address other topics. There are debates in the other topics that are presently in "suspended animation". I encourage you to look further down in the list of topics and ressucitate those interrumpted discussions.

I thank you all for your insightful contribution!

The discussion of large-scale pattern on marine biodiversity has proceeded through issues of comparability, highlighting the need for standardised procedures (both for identification of specimens and computation of indices). The functional role of species interactions, which are often rather species-specific both in the plankton and benthos has now been introduced as a major impact of biodivesity on biogeochemical fluxes.

1. Large-scale patterns of marine biodiversity

What are the large-scale patterns of marine biodiversity in Europe?

The myriad of metrics used to quantify betta diversity makes comparisons amongst studies cumbersome. Standard, agreed metrics must be devised is comparative analyses between estimates derived in different studies are to be used. This requires, most likely, an exercise to examine the extent of redundancy between metrics and to explore the statistical behavior of the different metrics.

Evolutionary patterns in marine biodiversity are only evident at the largest scales, for these patterns are blured by disperal events (only a few extreme events may be sufficient to lead to established populations), so that within the biogeographic provinces pattens seem to correlate with environmental variability. The potential of analyses of large data bases derived from existing sources to ascertain these correlations should be explored, although the patterns may be confounded by intercalibration problems. These are ever more important as the capacities to profesionally identify specimens becomes more rare. Perhaps technological tools may help to assist idenfication for some taxa.

2. Biogeochemical cycling and ecosystem functioning

What is the function of biodiversity in biogeochemical cycling and ecosystem functioning?

Trophic interactions between organisms, which are some time highly species-specific (e.g. parasites such as virus), are strong determinants of the fate of populations and, thereby, bulk biogeochemical fluxes. Trophic interactions among organisms explain blooms and population outbreaks, which have been reported to have major effects on both benthic (e.g. sea urchin ­ kelps) and planktonic (virus-bacteria) populations. Moreover, these trophic interactions, as represented in simple models using Lotka-Volterra- like expressions to link highly selective and less-selective predation with the competitive abilitiy of yield linkages between biogeochemical cycles and diversity than are normally ignored in the litterature.