Cormorants, Keys and Surveillance: A Day with Predation & Fisheries Expert Jake Davoile

He has the keys to fifty fisheries. Traps, night vision cameras and even laser deterrents, along with a unique knowledge of freshwater predators. Dominic Garnett went to meet the Angling Trust’s Jake Davoile, a keen angler and all-round nice guy; unless you happen to be a cormorant.

Jake Davoile Predator Advice Angling Trust
Alongside colleague Richard Bamforth, predator expert Jake Davoile works all manner of hours, day and night, to help clubs and fisheries.

It’s the single most divisive issue in angling today, but how much do most of us really know about predators like otters, cormorants and goosanders? Wading into the challenges faced by fisheries right across the South and Midlands is Jake Davoile, a man on a mission to help angling against predation. Surely an unenviable task in today’s world of rant first, think later?

“A lot of it is about education and perception,” he says. “People want a silver bullet against predators, but in truth there isn’t one. The real answer is more complex. There are many strands; culls are only one answer and there are a heck of a lot of other things we can also do to protect fisheries.”

Ranting about the issues is certainly no answer. So, while he can understand some of the current frustration, Jake is a keen advocate of a more rational, scientific approach.

The man the cormorants hate…

Meeting up on a Midlands lake, I’m about to discover just some of the ways Jake and the Angling Trust, funded by fishing licences via the Environment Agency, are helping to create more resilient, balanced fisheries. On this particular venue, which happens to be a Site of Special Scientific Interest (SSSI), issues with cormorants were once quite serious. “There were over sixty birds here some winters” he says. “It was getting to the point where they were trapping thousands of roach in the shallow end of the lake and local anglers thought they had disappeared.”

Cormorant predation prevention measures

Nor was it just fish that were affected. The local herons, in particular, found their favourite nesting island invaded, with trees literally melting away with the mess they made. Grebes also declined as their feeding grounds shrank. On a sensitive site, however, making loud bangs let alone shooting birds was out of the question. So how on earth could the cormorants be given the shove off?

Lasers proved to be the unorthodox yet key weapon in this case. “With quite big restrictions on site, these were perfect to shift the birds” says Jake. “Cormorants hate the beams being shone across their bodies!” I’m already imagining this must be one of the fun parts of the job.

If only it was as simple as flicking a switch, though. In fact, it took repeated pestering as they roosted on winter evenings. As with any site cormorants take a shine to, you have to be persistent. Steadily, though, they got the message, with numbers dropping from dozens of birds to just a handful. So, job done? Or would the ideal solution just be to cull them?

Myths and migrations

One thing most of us don’t fully appreciate about cormorants is their migratory nature. “If it was an typical ecosystem, a predator-prey balance would usually occur” says Jake. “But with cormorants there are an estimated 30 000 plus birds migrating every winter, from sixteen northern European countries. Even if it was permitted, shooting wouldn’t be the answer.” In fact, shots fired mainly serve to scare off excessive numbers of cormorants.  You couldn’t hope to wipe them out even if this was completely legal or desirable.

They are devious creatures too, he tells me. “They quickly learn when there’s a threat and where there isn’t. They’ll circle above fisheries and suss them out at first- anecdotal evidence suggests they they even recognise individual vehicles and rangers!” This means that fisheries have to use deterrents and back these up- whether with human presence, loud noise or another means.

Of course, with resident birds, shooting can also be an option, although legislation means this is restricted. This is precisely why evidence is so important (including the Angling Trust’s previous two Cormorant Watch initiatives), so that trouble spots can be targeted. Another help here can be the creation of an “area licence”. This means a group of fisheries across a wider area sharing a bigger cull quota, which can give added protection to particularly hard hit spots.

Prevention or cure?

predation cover fish fry refuge
Anglers don’t always like weed and cover, but for fish it is essential!

Naturally, the presence of predators is always only one side of the battle when it comes to fisheries. Having natural cover and areas of sanctuary are just as vital, unless you want your venue to be a soft target.

“I still sometimes hear from clubs and fisheries with predation concerns issues that started because of trees and other cover being completely removed!” says Jake. “Obviously we want to balance natural features with fishing access, but quality habitat is vital. Not all fisheries are great at leaving in the weed and cover that are so important to protect fish stocks.”

At today’s site are a wealth of natural features: Overhanging trees and bushes don’t just give fish cover, they help against bank erosion. Attractive fishing spots are broken up with rich plant life and artificial islands where fish of all sizes can find sanctuary.

“We are always advising fisheries to leave cover in where possible” says Jake. “It’s also about educating anglers about the value of this. Too many people are scared of weed, or are unwilling to change presentations or use a bit of watercraft.”

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Rude health? A thriving fishery is not one with no predators whatsoever, but has a healthy balance of predators and prey

Across the lake Jake shows me today, a combination of good habitat and cormorant deterrence have created a much healthier picture. There are quality roach and rudd in their thousands. As a result, predatory fish are also bouncing back, including some big pike.

This, of course, is another point to remember. “Predators are part of any healthy balanced fishery” says Jake. Back in the bad days, fish like pike were sometimes seen as vermin to be culled. We now know better, using science rather than scare stories to create better fisheries.

“It’s not predators per se that are the problem, but anywhere that an imbalance has occurred,” Jake says. “Waters with no predators at all are not desirable either. They can face other problems, such as stunted and diseased fish, and poor water quality.” This is a point we forget at our own cost. Is it sensible or even desirable to wipe out huge numbers of predators? Or should we be creating resilient habitats where hunters and hunted exist in balance?

Otters, traps and accidental finds

seal otter angling predation
Perceptions of anglers and the general public are radically different when it comes to the likes of otters and seals!

Another key part of Jake’s role is to help fisheries against otters. On top of literally hundreds of thousands of pounds invested in special fencing the Angling Trust have allocated on behalf of the Environment Agency via the Angling Improvement Fund, Jake is one of just a tiny handful of experts licensed to trap these predators, should they find their way into fisheries. Often in the wee small hours when the rest of us are in bed!

“It’s quite exciting!” he admits, “although it can be a race against time- because as soon as an otter gets into an enclosed fishery the watch is ticking.” Working with Natural England and the UK Wild Otter Trust is key where permissions and good practice are concerned.

So how on earth do you trap an otter? “Well, before any of that goes on, we try and find how it got in. Because if there’s a breach, it could quickly just happen again” he says. “Gates, joins and inflows can all be key areas- and it’s important for fisheries and clubs to keep things well maintained.”

Once security is checked, a trap can be laid. These are like mink traps, but much bigger to put it mildly. “First, we leave them outdoors for a while, so that they’re weathered and smell natural. We’ve used various fish oils and bait. We’ve also been experimenting with spraints from other otters.” One of the misconceptions about otters is that they will kill a fish and just leave it; more often than not, they will eat a portion of it and then return later, sometimes several times, to finish it off.

Does he consider otters a major problem? As an angler, he has experienced big “ottered” fish first hand. “It’s shocking to see a large fish that’s been had. It’s scary and not subtle in any way” he says. “But many of our barbel and chub rivers have had no apex predators like otters for years. That, along with limited habitats, and so many factors people are less aware of or willing to rave about, have led to quite an unnatural situation.”

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Jake fishes a small stream with his son; as a passionate angler besides a predation expert, he is as keen as anyone to see healthy, resilient fisheries.

Of course, it’s not always easy giving this message to anglers who might be faced with a sudden imbalance, such as a small river with a few but large barbel. Interestingly, though, the science often disagrees with the scare stories where fish are concerned. In fact, barbel and chub are quite far down the league table in terms of the prey most often taken, according to scientific studies. Nor is it all bleak, bad news: signal crayfish are heavily preyed on by otters, while they will also take mink. For anyone interested in the bigger picture and what current evidence tells us, a 2017 study by Bournemouth Universty, along with Martin Salter’s blog on otters are worth a read here.

Yet again, evidence has to come before emotion, and Jake worries that we focus a lot of negative attention on otters, while missing the huge number of deeper factors, from water quality to flow levels, which are so much less emotive but more important to preserving healthy fish stocks.

Things that go bump in the night

Looking at today’s sunny lake, you might assume Jake has a dream job. The reality is that predators rarely keep to our hours, however. He covers a huge amount of ground in a year- as his knackered looking Ford Galaxy will testify. He also has a bunch of keys to rival Alcatraz, which correspond to a vast number of fisheries.

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Just part of Jake’s key collection. Anyone might think he was a prison warden!

No two days are quite the same and he never knows quite what he’ll find. “I’ve had all sorts in this old Galaxy!” he chuckles. “Last time it was a swan that had got stuck down a large drainage gate. I had to wrap him up in my jumper and take him to be looked after!” Other random finds include a Perigrine falcon, found by his mother, which he first thought was a windup. It lived in his house for several days. Dr. Dolittle eat your heart out!

As for the most dramatic predation case he has ever witnessed, that would have to be the River Swale’s seal incident. “It had actually started feeding on angler’s halibut pellets!” he says. “The British Divers Live Mammal Rescue Team led the way on the case, who are an amazing group. They trialled a variety of nets. A few times there were near misses as it reached the mouth of the trap before shooting out at a hundred miles an hour! We got it in the end, though, with a giant net paid for by the Angling Trust because noone else would fund it. It was huge- I’ve never seen anything quite like it.”

A more balanced future for predators and prey?

In the long term, there are certainly no simple answers to predation, but there are so many ways fisheries can help themselves- and it’s good to know that along with fellow  predator expert and Angling Trust Fishery Management Advisor Richard Bamforth, Jake is there to provide support and advice. Both of these posts are fully funded by fishing licence income from the Environment Agency. They are available to advise any club or fishery in England and are funded by rod licence income in partnership with the Environment Agency.

Again, although many vocal anglers demand culls, these can only ever be a part of the solution. Evidence gathering and joined up thinking are key, and this starts on the ground with angling clubs and fisheries.

“There are lots of strategies that can help, and we’re always here” says Jake. “Much of the time it involves trialling different methods and carefully taking evidence. One strategy might not work, but by trying several, we can make a big difference. It’s not neccesarily about getting rid of all the predators on a water, but tipping the balance back in favour of the fish.”

jack pike predator debate
Predation is part of nature; it the where an imbalance occurs that there are issues.

Among the excellent examples of initiatives taken across the country, there are many good examples. Again, it’s not just “get rid of them all!”. In particular, Jake cites the excellent work of the River Avon Roach Project, and the many river keepers and rangers who are out there every day to protect fisheries.

Indeed, a sensible step for any venue or fishing club would be to appoint a predation post, with someone who regularly attends the fishery, who can trial deterrents and gather evidence. Indeed, where predator control is necessary, it is incredibly important to have the facts at hand. The moral of the story is simple: this is a fight we can win, but it won’t be with a shotgun. It will take evidence, action and initiative across the board, and this starts with angling as a whole gaining a better toolkit and broader knowledge of predation.

Free advice for your club or fishery: Who can I contact?

If your club or fishery has predation issues and you would like free advice from Jake or Richard then please use the contact details below.

Jake Davoile
Telephone 07949 703 206

Richard Bamforth
Telephone 07904 041 518


Further reading and useful links:

Angling Trust policy and action on cormorants and goosanders.

Angling Trust information and guidelines on protecting fisheries from otters.

3 thoughts on “Cormorants, Keys and Surveillance: A Day with Predation & Fisheries Expert Jake Davoile

  1. Thank you, that was a very informative article and Jake is so obviously doing a great job with wholeheartedly the right attitude towards predators. With education people will learn… I was very interested to read that signal crayfish are preyed upon by otters.
    I was fortunate enough to spend a week on the Bure around Horning this in October and I spent a day with a friend who lives nearby. When I commented about the number of cormorants, he said that it didn’t matter. There were so many baitfish that they, along with the resident high number of wonderful herons, did not adversely affect the river in any way. That was really good to know!
    Thanks again.

    1. Thanks for reading the piece and your feedback, Pete. It’s absolutely about learning, for all of us. Accepting challenges, yes, but also taking an evidence based approach and looking at all the strands and strategies that can help, not just culls. I can see that you’re one of those that can see this. The positive feedback is appreciated though- sometimes on the subject of predation, with the level of emotion and anger it raises in some quarters, it can feel like I am the prey! The bottom line is that we’re all in it to help- and I wanted to show the work that goes on behind the scenes with folks like Jake, working their socks off.
      Dom Garnett

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