We have been busy lately helping the European Eel fulfill its migratory desires!
The European eel (Anguilla anguilla) is a species of Eel, a snake like, catadromous fish. They can reach a length of 1.5 m (4 ft 11 in) in exceptional cases, but are normally around 60–80 cm (2.0–2.6 ft), and rarely reach more than 1 m (3 ft 3 in).
There are still elements of the life cycle of the eel which area mystery but the bits we do understand are fascinating.
Unlike many other migrating fish, eels begin their life cycle in the ocean and spend most of their lives in fresh water, returning to the ocean to spawn and then die. In the early 1900s, Danish researcher Johannes Schmidt identified the Sargasso Sea as the most likely spawning grounds for European eels. The larvae (leptocephali) drift towards Europe in a 300-day migration. When approaching the European coast, the larvae metamorphose into a transparent larval stage called “glass eel”, enter estuaries, and start migrating upstream. After entering fresh water, the glass eels metamorphose into elvers, miniature versions of the adult eels. As the eel grows, it becomes known as a “yellow eel” due to the brownish-yellow colour of their sides and belly. After 5–20 years in fresh water, the eels become sexually mature, their eyes grow larger, their flanks become silver, and their bellies white in colour. In this stage, the eels are known as “silver eels”, and they begin their migration back to the Sargasso Sea to spawn.
The European eel is currently classified as ‘Critically Endangered’. Overall numbers have significantly declined over the last 25-30 years and the reasons for this are suggested as being a combination of habitat loss, barriers to migration, parasites, pollution, over-fishing and climate change affecting oceanic currents.
The barrier to migration problem is one area that can be improved and Kingcombe Aquacare Ltd have been working closely with the Environment Agency to improve things for the humble eel. We design and fabricate effective eel pass systems to suit a wide range of conditions and our skilled site teams have been carrying out installations at many locations in the South of the UK.
John recently started a new LinkedIn discussion regarding the use of herbicide against non-native aquatic plant species. Here’s what he wrote.
“Over the last 10 years most approved aquatic herbicides have been removed from the market. Now it would seem that Glyphosate is the next target to come into the sights of the EU legislators. I suspect that all environmentally conscious people would prefer not to be introducing chemicals into the environment unnecessarily. However, the potential loss of Glyphosate, which in the form of Roundup Pro Bio is deemed to be one of the safest products for use in or near water, would present us with real challenges, not the least being the control of non-native species such as Japanese Knotweed, Giant Hogweed, Floating Pennywort to name but a few.
As a responsible company working in the field of water management and maintenance, Kingcombe Aquacare is keen to find alternative procedures if they exist, but for some of these pernicious plants, which are destroying our native habitat, often in SSSIs, spraying with Glyphosate is the only commercially viable means of control.
I would be interested to know where other Chartered Environmentalists stand on this issue, and whether there are alternative non-native invasive weed control strategies that are commercially viable and successful. Indeed, I would be keen to know where the Institute stands on this issue!”
The ramifications of potentially losing the last remaining effective herbicide are huge and will spark many discussions of how best to control infestations of these non-native plants
An example of success achieved by good design, strong partnership working and experienced installation teams.
We have recently completed another eel pass and fish baffle installation for the Environment Agency, this time in Frampton Cotterell, on the Bristol Frome in Gloucestershire.
Working very closely with the Environment Agency project manager, Gareth Varney, and Fisheries Officer Jody Armitage, we installed one of our jointly designed cassette type eel and elver pass systems on an existing weir, to help improve eel migration. The recycled plastic fish baffles were installed on the concrete weir face to improve the ease of passage for trout and coarse fish. Both systems were designed to minimise the impact on flow measurement accuracy of the weir and on flood warning capability.
Water level was higher than expected so conditions were challenging but not insurmountable. Our site team were able to manage the water effectively by deploying sand bags and flow deflectors to divert it away from the works area. This facilitated the installation of fish baffles and the eel pass, while maintaining constant water flow downstream.
Our work was completed safely, on time and to budget. Gareth Varney, Environment Agency Hydrometry & Telemetry Programme Manager commented;
“We are delighted with the new eel pass installed by the Kingcombe team. They were able to complete the installation under challenging conditions but despite this the end product is perfect. It has not compromised the operation of our existing weir and has hopefully improved migration of fish further up the Frome catchment and should be another positive step in the right direction in the battle to reverse the decline in the European Eel population”
Wednesday 6th April 2016, it’s a big day for Kingcombe Aquacare.
Today at 12:00 noon we are going to launch our new weed harvester “Jenny”. She is being named Jenny in memory of our dear friend and colleague, who lost her battle to cancer in 2011.
The boat is launching at Coldharbour Boat Ramp at Ham near Taunton (which we built for the Environment Agency); this will be signed from the A358. There is space to park. The postcode is TA3 5NZ at the junction of White Street and Knapp Road.
If you are local and have a spare hour please do come and say hello. You can see the boat at work, either from the bank or jump in the passenger seat and talk to the operator as you go up river. Come and chat to our staff either about the boat or any other service that we can provide. We will be on site from 11am until 3pm, there will be pasties and hot drinks available.
“Jenny” is joining our other AquaTractor “Gordon” to deal with the increased workload to provide a reliable and flexible service.
Our AquaTractor weed harvester offers the following benefits for aquatic weed control:
A reliable, productive workhorse
Weed cutting depth to 1.950m
Weed free helix screw propulsion unit, directional through 180°, with hydraulically adjustable operating depth
Shallow draft (laden draft of only 325mm)
Hold capacity up to 5m³
Discharge speed less than 2 minutes
Less than 30 minutes to launch and prepare for operation = maximum productivity
Our fisheries team have been out and about undertaking some fish survey work.
Jon Trevett sent in some photos from site including a magnificent eel. It is so nice to see such a stunning specimen as our eel population is a fraction of what it used to be.
Our bespoke eel pass design and installation work in conjunction with the Environment Agency (read more here) is helping to improve migration of elvers and mature eels, which goes a little way towards improving their chances of increasing in numbers once again.
Have a look here to read more about our eels – they are on the ‘Red List’ of endangered species.
If you own or manage a section of river with man-made obstacles to fish and eel passage we may be able to help. Nick Williams is the man to talk to 01460 279 200. If you need our fishery expertise please contact Scott Rice on the same number.
Kingcombe Aquacare Ltd were engaged to fabricate and install a weed rack as part of the Environment Agency’s Water Level Management Plan at Bodenham, near Salisbury. The rack was made to EA specifications in our workshop at Crewkerne. The process included full assembly in our yard (pictured above) to check for accuracy. The structure was then sent away to be galvanised to the required standard. It was delivered to site in kit form and installed into the river.
Rycote Park was the site of an Elizabethan royal palace, and the main house still incorporates part of that original building. The extensive grounds include a lake of almost 5 hectares, part of which dates back to Elizabethan times but which was considerably enlarged and landscaped by Capability Brown in the 18th century. Very little work had been done to the lake since that time. By 2000 it was heavily silted up, with only 0.5m depth of water over most of its surface area, and seriously encroached by alders, willows and marginal vegetation around the greater length of its banks.