2005 - Whitby Naturalists

The researchers fear that ecosystems afe fragmenting with predafor
species becoming separated from their prey as the smaller prey species
with their shorter life-cycles move north more quickly than the larger,
slower -growing predators.
It rnay be thar species not m()ving tlorth are able to deal with the
changes in temperature and acidity, which infornied t*servers almost
universally considcr to bc the result of hurnan activi.flr. The less
optinristic possibiliry is that their immobllity is the result of their l-raving
highly specialised habirat rcquirements which have not yet been
discovcred by science, and which are not ft;u1d further north, so that
as climate change continues they will become exlinct'
Some workers are worried that if trends continue, by 2050 commerciai
species such as bltre whiring and redfish will have gone completely,
tiiough thcy may be replaced by bib and other species found at present
in more southerly waters. Cr:rtainly some exotic catches are already
being rnade like the rainbow wrasse caught this year on the Bsscx coast-
Forms that are usualiy found off the Cornish coast such as pilchard and
sea hass are appcaring in larger numbers in the North Sea. The
numters of scluid now in our waters is bccoming unreal according to a
Nortl-rumberland fisherman quotecl in The Guardian.
It is r,ot just fish thar are showing change. The Intemational Council
for the Exploration of the Sea (ICES) report that plankton populations
arc also affected. Up to the 1970s the phytoplankton had a pattem o{
spring and autumn peaks in numbers ("blooms"). Front thc 80s these
blooms havc merged into a more continuous production in numbers-
This has led to gleater amounts of these algae treing present in recent
years with the proportion of diatoms decreasing while that of dinoflag'
ellates has increased, thereby provicling more food at the base of the
food wcb. Populations of planktoni.c crustacea too are changing. There
has been a huge drop in rhe numbers o{Caldnus finmarchiclttsr one of the
most imnortant food sources for commerciallv valuable fish' At thc