Found during a routine survey of the river Thames in London yesterday (Oct 7th ’11). The juvenile short-snouted seahorse measured 5cm and can reach 15cm in length.
Emma Barton is a fisheries officer with the Environment Agency and has jumped the gun with her sample of one:
This is a really good sign that seahorse populations are not only increasing, but spreading to locations where they haven’t been seen before.
Now, the species is found on the south coast of the UK but has never been seen so far upriver so I’ll giver her that, new location but finding one seahorse is not representative of increasing seahorse populations.
That aside the last time I was in London the Thames was rank! how a wee population of seahorses could move up it, I dunno.
I wonder what their environment there is like? I’ve never heard of seahorses being euryhayline, something to read up on.
OK, seahorses are euryhaline creatures. However, adaptation to salinity depends on their stage of maturity. Adults can tolerate a salinity of 6 ppt or lower, while juveniles can only tolerate a salinity nearer 15 ppt. This information is not on the same species as that found in the Thames but hey, it’s something!