The news come as some relief set against the EU commercial fish stock scenario  Work by the ScottishEnvironment Protection Agency (SEPA)  completed in the spring and repeated in the autumn is carried out to audit and establish the health of the river fish populations. 

Diversity and abundance of estuarine fish is a barometer of the health of the marine environment as they are mobile, relatively long lived and found near the top of the food chain.

GLASGOW AND THE CLYDE

Of Glasgow,  Myles O’Reilly,  (right) Senior Specialist Scientist in SEPA, said: “We looked at the fish species that occur right in the centre of Glasgow close to the old Suspension Bridge at Carlton Place.

"Traps set overnight this Spring highlighted the presence of shoals of  (right) Perch and Flounder, aswell as Sticklebacks.  Migrating Salmon (lower right) Smolts were also captured and there is evidence that Elvers (young stage of eels) and Lampreys also pass through the city centre on route to freshwaters.”

Further downstream at the mouth of the River Cart, in slightly saltier waters, eight fish species were caught by trapping or using small seine nets. This included shoals of Gobies and Sprats along with Flounder and Salmon Smolts as well as species typical of saltier estuarine waters such as Eelpout. 

He adds: “It’s clear that the river supports populations of resident and migratory fish even in the middleof the city.  This will come as no surprise to birdwatchers, as fish-eating birds such as Cormorants, Guillemots and Mergansers are regularly seen feeding on the river.

Flounder are a favourite prey and although these flatfish are usually thought of as sea fish, the young stages may venture far upstream into freshwaters.”
SEPA does not harm fish during these surveys and the fish are returned to the water. Further Clyde surveys are planned in the autumn.

Sampling involves the use of a variety of fishing methods, including seabed and mid water trawls from SEPA’s survey vessel and, in the intertidal areas, using seine nets operated by hand or setting up Fyke nets to trap the fish overnight.


THE FORTH ESTUARY

“The Forth Estuary with its extensive mudflats is relatively rich in fish species and acts as an important nursery ground for young marine fish," says O'Reilly.

"In Spring we undertook surveys of the fish that occur in the lower estuary close to the road and rail bridges and revealed 14 different species of fish. Trawling of the seabed between Port Edgar and Limekilns found the young stages of many commercial species such as Whiting, Cod, Dab, Plaice and Lemon Sole.” 

Among the more colourful fish observed was a young Tub Ggurnard (below) with beautiful blue-green pectoral fins, and scientists also caught a Sea Mouse (right), a marine worm found in the North Atlantic, the North Sea, the Baltic Sea and the Mediterranean. 

Myles notes  “Traps set overnight for shore fish at Limekilns (above left) captured Flounder and Eelpout.  Eelpout are unusual among Scottish fish in giving birth to live young. They are cool water species and thought to be potentially sensitive to global warming. 

"We also use hand-operated siene nets in shallow bays to sample huge shoals of Sprat, important food for seabirds, such as Terns, nesting on nearby islands in the Firth of Forth.”