EA River Glen fish survey report

EA River Glen fish survey report


ea

Summary:

• Seven sites approximately 100m each on the Glen system were surveyed between February and November 2017; five of these sites were surveyed using electric fishing, one seine netting and a 12km side scan survey was undertaken on the lower river between Surfleet Seas End and the “Flats” upstream of West Pinchbeck. One electric fishing site was undertaken on the Bourne Eau at Mays Sluice in Bourne, with the rest of the drain being side scanned in early December to assess shoaling fish in colder temperatures.

• Two of the sites near Waterside Garden Centre were undertaken as part of specific monitoring work for the off channel habitat improvement scheme.

• Sixteen species of fish were recorded and a total of 14118 fish were captured;

• Pike and dace were the most widespread species, being recorded at seven and six sites respectively.

• Roach were the most numerous species and also had the highest biomass.

Health of fish population:

• Results from the upper river electric fishing sites are promising, fifteen different species were captured from the sites with dace populations particularly strong in areas off the back of riffles or deeper holes in the bed at places like Kates Bridge and Carlby. Wild Brown Trout are present as well as Eel, which is classed as critically endangered, Bullheads and Brook Lamprey; all of these species are on the BAP (Biodiversity Action Plan) list.

• The main restriction on fish in the upper river will always be hydrological. The river depends on groundwater from the Lincolnshire Limestone, as levels drop off during dry periods it negatively affects the river. The Environment Agency runs the water transfer scheme from the River Gwash via pipeline into the Glen at Essendine; this was turned on in August to supplement flow coming down the river. Without this the river would be in danger of stopping flowing and drying up down to Kates Bridge. The types of fish species present in the upper system will always be sensitive to flow rates, for spawning, for water quality and for creating habitat and refuge.

• The lower river does contain good shoals of roach, tench and some carp but locating them as an angler can be difficult and conditions need to be right to catch. Bream haven’t been captured in large numbers in the river for a long time now so further investigation on the river in the future will concentrate on these. Excessive weed growth will always be a problem over summer for years to come, the combination of nutrient rich silt and water combined with low flows make for ideal growing conditions. It remains a river where if you put the time in there are good fish to be caught.

• The fish population in the Bourne Eau is being limited by the level of sediment present. There may be future benefits for both flood defence and fish communities in the future from sediment removal.

Follow this link for the full report: River Glen survey report 2017