Angling (fishing) contributes around £100 million to East Anglia’s tourist industry each year – the sale of rod licenses alone brings in nearly £3 million. According to the Environment Agency the Broads National Park is arguably one of the most important natural freshwater fishery resources in the U.K. Yet many local children, when asked to name what types of fish live in the nearby rivers or broads, list a range of marine or tropical fish from clown fish (Nemo), snake head fish (at least it lives in freshwater) to salmon, cod, tuna, sharks and herring! Only occasionally does the word pike pop up. If some of the children have been fishing with their father, uncle or granddad – never mum, aunt or gran – then carp and perch might be mentioned.
Admittedly part of the problem is the difficulty of seeing what’s underwater, so the assumption is often “nothing much”! Added to this is that the majority of nature programs on TV focus on the “more exciting” wildlife to be found in the sea and abroad. To celebrate World Environment Day (5th June) this week’s post is dedicated to raising awareness of the fish that live in the Broads National Park’s freshwater habitats – its 6 river’s, 63 broads and myriad of dykes. The need to look after these precious habitats is vital not only for the animals and plants that live here, but also because they’re where the water in our taps comes from!
In the U.K. freshwater habitats comprise about 12% of our total land surface and are home to 42 species of native freshwater fish, 29 of which occur here in the Broads National Park. The Prezi Presentation (link below) will introduce you to our 5 favourite fish found in the National Park and give you the chance to see Emily Rose Winter talking about how she’s been tracking pike and bream in the Rivers Bure, Thurne and Ant for her PhD. Then of course there’s a selection of activities for you to do. This week’s main activity is to write a fish or river inspired poem and to help free your inner poet there’s a different poem to read for each fish.
Historically the waterways (rivers, broads and dykes) of the Broads National Park abounded with fish, not only in terms of numbers (it was considered normal to catch 75kg of fish in a day’s fishing) but also variety of species. The water was clear and full of plankton and aquatic plants providing food, shelter and safety from predators for zooplankton, invertebrates and fish. Sadly, since 1900 these conditions have changed as the impact of overfishing (before 1870 there were no regulations), pollution, sedimentation, loss of habitat from the complete drainage of marsh and increased motor boat activity took their toll. The result has not only been a decline in the overall abundance of fish in the system but also the favouring of species, such as bream and roach, that can cope with the new conditions (turbid waters, algal blooms, loss of aquatic plants and animals such as leeches, molluscs, and snails) over those such as perch and rudd.
In order to counter these threats, we need to understand the ecology of the Broad’s freshwater habitats – the interactions between the animals and plants and environmental factors such as pH, salinity, temperature and toxins. With this knowledge organisations such as the Environment Agency, Broads Authority, Wildlife Trusts and others are better able to advise on how to manage and protect the freshwater habitats as well as undertake large scale projects to restore those that have been degraded by a combination of human actions. A £4.5 million restoration project is currently underway at Hoveton Great Broad (Click here to read more) building on knowledge from previous restoration projects such as those at Cockshoot Broad and Ormesby Broad.
The Broads National Park is unique in Britain as its 200km of waterways are clear of all barriers to movement such as dams, weirs and locks – great for boating enthusiasts and as it turns out fish scientists! Emily Rose Winter has been conducting the first large scale fish tracking study ever to be done in the Broads National Park for her PhD. She has been investigating the movement of pike and bream in the Bure, Thurne and Ant river valleys and loves the fact that the lack of barriers means it’s possible to study the fish behaving “normally”. By normally she means they are able to move unrestricted throughout the system to find food, breed, escape predators and in response to changing environmental factors such as temperature. In other parts of the country the fish’s behaviour will be modified by barriers such as dams and locks restricting where and how far they can go.
One way the data generated by Emily’s research could be used is to help organisations protect fish from threats. One of the main natural threats in the Broads National Park is saltwater. Not all fish are able to live in salt water and freshwater fish range in their ability to tolerate salt in their environment. Some freshwater fish like the three-spined stickleback have no problems others, like pike and bream will die if the salinity becomes too high and they cannot escape by moving away. The proximity of the sea to the Broads National Park and the tidal nature of its rivers means that the salinity of the water frequently fluctuates – the degree to which it does varies with location. For example, salinity is high in the estuarine conditions of Breydon Water and low to non-existent in the upper reaches of the Bure, Thurne and Ant rivers. These areas are only affected by salt water during extreme tidal surges. However, with climate change and rising sea levels the frequency with which salt water extends into the upper reaches of the Park’s river valleys is set to increase. Understanding where fish go and what they do when salinity levels rise will help put measures, like the barrier at Potter Heigham, in place to protect them.
To find out more about Emily Rose Winter’s work watch her interview in the Prezi presentation.
Many thanks to Mark Barrow at Beneath British Waters and Emily Rose Winter for allowing us to use some of their lovely fishy photos!
- Fantastic footage of U.K.’s freshwater fish shot by Mark Barrow of Beneath British Waters. Click here to watch.
- Great short videos of wildlife in the Broads National Park by Liam Smith, producer of “A Shot of Wildlife”. He’s based in Norwich and below are links to the video’s featuring fish in the Yare and Wensum. Check out his youtube site for more local wildlife shorts.
- Link to the Eel Lifecycle featured in the Prezi presentation. Click here to watch.
- Interested in Eels in Norfolk find out about the Glaven Eel Project here.
- Link to TedEd’s Earth School with 30 quests for students to celebrate, explore and connect with nature. All part of World Environment Day on June 5th. A definite must!
- The Royal Society for Biology have put together a pack about some of the freshwater animals in the U.K. – not just fish!
- The water cycle brought to life through a lovely artwork and animation. Click this link to watch.