Seahorses in non tidal Thames

[534l4rk]

Not seen anything on this on the Forum. “Following on from the discovery of sea horses in the tidal Thames 2 years ago larger variants are reported to have been seen this year at Dockett Eddy Shepperton and Chertsey Meads. These rare creatures measure up to 30 cms in length and are thought to be moving into non-tidal waters due to the scarcity of seagrass in their saltwater domain. The flooded fields along the river this year are enabling them to feed on submerged grass on the land. Since the unconfirmed sitings at Cookham, Berkshire County Council in conjunction with the Aquaculteral Research Institute are understood to be preparing for the establishment of a colony on the south bank approaching Dorney lock. Boaters are to be requested by the Environment Agency to report all sitings to lock-keepers who will be handing out information leaflets asking that they should not cause excessive wash as these creatures are best seen in smooth waters where they occasionally rear up above the surface.”

There are over 50 species of seahorse all having the generic name hippocampus (ancient Greek hippos = horse and kampus = sea monster).
For further reading see :- hippocampus bargibanti (Pigmy Seahorse)
hippocampus aimei (Freshwater Seahorse)
hippocampus lirpa lofo (Giant Seahorse)

 

[dash300]

Not seen anything on this on the Forum. “Following on from the discovery of sea horses in the tidal Thames 2 years ago larger variants are reported to have been seen this year at Dockett Eddy Shepperton and Chertsey Meads. These rare creatures measure up to 30 cms in length and are thought to be moving into non-tidal waters due to the scarcity of seagrass in their saltwater domain. The flooded fields along the river this year are enabling them to feed on submerged grass on the land. Since the unconfirmed sitings at Cookham, Berkshire County Council in conjunction with the Aquaculteral Research Institute are understood to be preparing for the establishment of a colony on the south bank approaching Dorney lock. Boaters are to be requested by the Environment Agency to report all sitings to lock-keepers who will be handing out information leaflets asking that they should not cause excessive wash as these creatures are best seen in smooth waters where they occasionally rear up above the surface.”

There are over 50 species of seahorse all having the generic name hippocampus (ancient Greek hippos = horse and kampus = sea monster).
For further reading see :- hippocampus bargibanti (Pigmy Seahorse)
hippocampus aimei (Freshwater Seahorse)
hippocampus lirpa lofo (Giant Seahorse)

And magically attracted to anchors!

 

[sarabande]

that's a bit of a coincidence ! The NFU (National Farmers Union) and the Environmental Agency has a research program on invasive species

(Background link)

http://books.google.co.uk/books?id=...Bg#v=onepage&q="invasive species" NFU&f=false

and it seems that not only is the American Crayfish moving from a freshwater habitat to a brackish one (with a concomitant increase in size [some reports of a 30% increase in body length]) to the outer edges of the Thames near Canvey Island and as far as the Medway) but the spread of 'grazing' seahorses in flooded water meadows may inhibit the extensive (and very expensive) overflooding works near Dorney if bans on use of the area are put in place under the EU directive, Drinking Water Directive (Council Directive 98/83/EC of 3 November 1998 . Some concern has also been expressed by water extraction utilities, e.g. Thames Water, that the decomposing skeletons could (if the animal's population increases in the anticipated exponential manner) tend to block the diatomaceous filters commonly used at the primary intake stage of the drinking water treatment works. This is because the exoskeleton of the seahorse is made from a hard chitinaceous substance (keratin) which takes a long time to break down.

The NFU also has concerns that the move to control farming application of dung in Nitrate Sensitive Areas in the Thames Valley may be opening up the improved grassland to invasive species, as the water quality in flooded areas is very much higher than it was even ten years ago. BDO (Biological Dissolved Oxygen) figures, for instance, is one of the most important and useful quantitative parameters indicating the organic strength of waste water. Increased BDO (due to increased water animal numbers) may make treatment of drinking water for humans and livestock very much more expensive.


Last year there wasa Defra consultation process on Aquaculture, looking in particular at Water Safety, and Sustainability.

http://www.defra.gov.uk/consult/files/120112-aquaculture-consult-doc.pdf

The document makes it clear that we cannot afford to allow uncontrolled proliferation of invasive species, such as the seahorse, in our rivers. (There are also rather pedantic issues of scientific nomenclature to be considered. Specie diversification requires a more specific taxonomy, and perhaps a change of name from seahorse to river horse. That is matter for the future though, and not for this forum.)

 

[Tam Lin]

What is the date today?

 

[534l4rk]

and it seems that not only is the American Crayfish moving from a freshwater habitat to a brackish one (with a concomitant increase in size [some reports of a 30% increase in body length]) to the outer edges of the Thames near Canvey Island and as far as the Medway) but the spread of 'grazing' seahorses in flooded water meadows may inhibit the extensive (and very expensive) overflooding works near Dorney if bans on use of the area are put in place under the EU directive, Drinking Water Directive (Council Directive 98/83/EC of 3 November 1998 . Some concern has also been expressed by water extraction utilities, e.g. Thames Water, that the decomposing skeletons could (if the animal's population increases in the anticipated exponential manner) tend to block the diatomaceous filters commonly used at the primary intake stage of the drinking water treatment works. This is because the exoskeleton of the seahorse is made from a hard chitinaceous substance (keratin) which takes a long time to break down.

And to think I was worried about the decline in the species !

 

[oldgit]

Did anybody else see the notam about speed limit on non tidal Thames being increased to 21kph after 17.00 hours.

 

[534l4rk]

Did anybody else see the notam about speed limit on non tidal Thames being increased to 21kph after 17.00 hours.

Presume small print stated that this did not apply to vessels travelling between locks !

 

[oldgit]

Presume small print stated that this did not apply to vessels travelling between locks !

Missed that bit ..........but did see new H&S Byelaw 69.
All vessels navigating on Thames must now carry a sufficient quantity of sunglasses and suncream for ALL passengers and crew !
This must located and placarded in a prominent location in case of emergencies !