Over the last few years there has been changes in our local waters, with more exotic species venturing to our land and many of our locals coming under threat.
There are many main UK species which could be in danger as our climate changes. Tha Atlantic Cod is an important fish in British waters as it is a valued food source. But stocks of the species are depleting. This is mostly due to over fishing but Atlantic Cod are also unsuccessful at adaptation and ocean warming may force the Cod further North causing a large drop in numbers. Food source is also an issue for these fish as Plankton will be affected by climate issues too. One type of plankton that are suffering are Calanus Zooplankton, shrimp-like Copepods which used to be abundant in the Atlantic. However, since the 1940's there has been a 60% drop in Calanus Zooplankton overall, and studies have shown that numbers of colder species of Zooplankton such as Calanus finmarchicus have decreased and warmer species such as Calanus helgolandicus have increased.
Sandeels are also under threat due to sea change. They are important to the Atlantic waters as they feature heavily in the food web. Numbers of sandeels is declining and there is an obvious relationship between this reduction and positive oscillation, with egg and larval numbers lower than ever. Low sandeel numbers may also explain why there has been less sea bird nesting and breeding across the coast.
On the other side of the coin, as the seas temperatures rise we have seen many more organisms lose their way and turn up off our coasts - causing new concerns. Jellyfish have been the most frequent new visitors to our usually chilly shores, with many exotic, tropical and poisonous species being spotted. The Portuguese Man of War, a siphonophore often referred to as a Jellyfish, has been the highest recorded species to be found in UK seas but The Compass Jellyfish, Mauve Stinger, Blue Jellyfish, Moon Jellyfish, Lion's Mane and The Amazon Jellyfish are all examples of poisonous Jellyfish which have raised alarm with UK scientists and coast guards. These are unknown species to many UK beach-goers, as their presence is so unusual here, and some have life threatening stings.
But it is not just Jellyfish that have been making appearences. A nine foot Blue Marlin was recently found off the coast of Wales. The Swordfish is usually found on the other side of the Atlantic, but turned up dead off a Bay in Pembrokeshire. Although its cause of death is unknown, the Marlin is reported to being particularly thin and it is thought to have been struggling to find appropriate food in our cooler climate. The fish's appearence is under debate - some claim the it is not the victim of climate, just a 'straggler' who lost its way, but others believe that this is unlikely and the fish would have been lured over by increased temperatures and it is a warning as to what will happen if our seas continue to get warmer.
As temperatures increase it seems we will lose many of our usual species in favour for new ones; possibly causing a complete overhaul to the delicate balance of our oceans. There will be new predators and new pray, and sadly, from previous research we already know that 'invasive' species always have a negative effect.
