EAST YORKSHIRE CHALK RIVERS TRUST Newsletter No 3 - May 2009 Aike Fry Refuges Eske Borrow Pit Aike Beck, a tidal tributary of the River The banks of this 30 hectare flood storage and Bishop Burton Agricultural College to Hull, was diverted in the 1980’s and lake next to the River Hull near Beverley undertake some bank restoration work. the channel course returned to arable was becoming badly eroded due to the The project was completed using land. open aspect and the prevailing wind. This natural Willow material from the site. This In compensation for this loss of site is adjacent to the Pulfin Bog, a SSSI was placed in the marginal area as an habitat, several channels were and important bird migration route. effective method of breaking the waves excavated in the berm of the main The Trust entered into a partnership and enabling the growth of reeds to river to create sheltered areas for fry. arrangement with the Environment Agency stabilise the banks. After 20 years, these off-river channels had become silted. A project was set up in partnership with the East Riding Fisheries Consultative Association to Golden Hill reinstate this important habitat. Fencing On site supervision of the work was undertaken by the Trust. The The effects cattle can have on a fragile channels were reshaped and riverbank is well documented. deepened to improve the habitat. The middle reaches of the West Beck The effectiveness of the shelter were being heavily impacted due to an channels will be monitored in inadequate electric fence. partnership with the Environment The Trust using EA funding in Agency. partnership with the Golden Hill Fishing Club erected a new, more substantial fence. This project has helped protect over 1900 metres of river bank. East Yorkshire Chalk Rivers Trust 1 Newsletter 03.pmd 1 14/10/2009, 10:21 Gypsey Race Fisheries Survey 2008 Gypsey Race Following the 2008 Surveys on the Gypsey Race is a groundwater fed, Gypsey Race the Environment winterbourne chalk stream which Agency gave consent to reintroduce discharges direct into the North Sea at brown trout to the stream. This was Bridlington. Part of the approximately undertaken with the installation of a 25km long watercourse is dry for several hatching box filled with gravel with the months of the year with the exception of trout eggs and gravel layered to the deeper pools. Several species of fish imitate a natural trout redd. are believed to survive within the stream with reports of large trout being caught. spot-sampling used for the chemical Surveys have been carried out on the component of the GQA scheme. stream in order to establish the baseline Minnows in spawning colours Samples have been collected using fish population prior to instream habitat three minute kick samples and the improvement works. These works are number and species of macro- designed to protect the existing invertebrates present can be used to population of fish and enhance the natural calculate a grade for the river based on environment to increase recruitment and the pollution tolerance of the species juvenile survival. present. Grade ‘A’ represents very good Biological Surveys have been carried whilst Grade ‘F’ represents bad biological out on this watercourse since 1990 community present. through kick sampling and King’s College carried out eel specific surveys in 2005. Discussion The results of these surveys are included Survey results for Gypsey Race show fish in the report. A typical East Riding of Yorkshire chalk present at all survey sites in varying stream trout numbers. Minnow and sticklebacks are Methods the most abundant species and are a 2008 Fisheries Surveys fished using electrofishing techniques good food source for trout and many bird All sites were surveyed using electro- similar to those employed in 2008; species. These species are tolerant of fishing. This is a common fisheries survey however these were fished at a very slow poor environmental conditions and will tool, which enables a stretch of river to be pace and all species other than eels survive in isolated pools as the stream surveyed using a localised electrical largely ignored. The slow pace allows the dries during the summer. current to temporarily ‘stun’ fish allowing electrofishing gear to have a greater effect The mean daily flow data shows that them to be netted easily. They are then on deeply burrowed eels and results in a between August and November the placed in a recovery bin or keep net until much higher catch rate. the end of the survey when they are identified, measured and a scale sample Biological Surveys taken before being returned to the river. These have been carried All sites were surveyed over 40-50m out as part of the General lengths of stream with ‘stop-nets’ used to Quality Assessment (GQA) reduce the risk of fish evading the scheme. The biological electrical field. Minor species were component of the GQA recorded on a log abundance scale with scheme is based on major species individually counted. monitoring the macro- invertebrate communities 2005 King’s College Eel Surveys of rivers. Invertebrates are King’ College carried out surveys on the used because they eel populations throughout the River Hull respond to the physical Catchment and the East Riding of and chemical Yorkshire to determine the current state of characteristics of the river, the eel populations. This was part of a and are affected by nationally funded Environment Agency pollutants which occur project. infrequently and which can The two sites on Gypsey Race were not be detected by the 2 East Yorkshire Chalk Rivers Trust Newsletter 03.pmd 2 14/10/2009, 10:21 stream is at most risk of drying up. In 2005 the level was extremely low and flows did FOCUS ON THE not recover until April 2006. Multiple years WATER SHREW of low water levels will exacerbate the existing flow problems within the stream This elusive small mammal can be for fish. Low flows are likely to result in found in chalk stream habitats and is an warmer water temperatures and indicator of good water quality. It is decreased oxygen levels. often overlooked and under-recorded The absence of brown trout in the as it is very rarely seen. Adult water shrew showing white tips results suggests that the conditions during Measuring around 10cm in length to the ears the summer are not favourable to support and weighing between 10 and 22 this species or that the surveyed sites do grams, the water shrew has a not hold trout. Surveys could be carried characteristic dark coat with distinctive out later in the year when less water is white under parts and often has white present so that pools can be targeted ear or tail tips. which must be holding trout if they are It is semi-aquatic and has several present. adaptations for this lifestyle, including a Two large trout caught during the thick coat with dense undercoat and King’s College surveys suggest that the short bristly hairs along the inside of its species may be present within the system. hind feet and the underside of its tail. These may have been sea trout, which These help it to swim and dive for its aquatic prey. migrated up the stream to spawn although Aquatic prey remains are clearly seen From late spring onwards, the Water this has not been confirmed through scale when viewed under a microscope analysis. The presence of these trout Shrew may have as many as three indicate that this species may be present litters in the year, each containing as water shrew is the only shrew species to within the system or the potential exists to many as eight young. Like many small catch aquatic prey. Surveys for water develop a population should migrating mammals they are short lived and many shrews can be carried out by using bait fish be able to spawn successfully. Further youngsters don’t survive more than a tubes and then looking at any scats surveys targeting trout during the few months. Adult water shrews have (droppings) found in the tubes, under a migration period would allow better been known to survive 18 months but microscope. analysis of the situation regarding this more typically live for around 9 months. Remnants of prey species, including species. Thus a youngster born this summer will freshwater shrimp, water slater and The presence of eels in Gypsey Race hopefully survive the winter and breed caddis fly, are clearly visible in the scats is important. The life cycle of eels is fairly the following year, keeping the overall when viewed under a microscope, with complicated with adults migrating to the population stable. limbs often seen and the whitish Sargasso Sea to spawn and elvers As mentioned earlier, aquatic prey exoskeleton of freshwater shrimp also (juvenile eels) returning to the UK. Eel form a significant part of its diet and the obvious. recruitment to the UK is known to have crashed in the early 1980’s and is now believed to be less than 1% of the within Gypsey Race, but no evidence of Recommendations historical levels for the country as a whole. their presence was apparent during the Fish surveys to be carried out to target The number present in Gypsey Race is fisheries surveys and it is advised that migrating fish species at appropriate time low and may be as a result of the low flow specific crayfish surveys be carried out in of year. summer conditions restricting movement order to establish their presence and Monitoring of the fish population for a within the stream. species. minimum of three years post habitat Biological surveys of Gypsey Race Of interest was the presence of water improvement works carried out since 1990 show a marginal voles at Site 4.