This article presents both sides of the UK cormorant management debate — and then makes the case that the dominant conservation narrative is incomplete, intellectually lazy, and ultimately harmful to the very ecosystems it claims to protect. We cite sources throughout and invite challenge on every point. If you disagree, bring data. That's the whole point.
The Conservation Position
The mainstream conservation argument against cormorant management is well-rehearsed and powerfully amplified. It goes broadly like this: cormorants are a native species doing what they evolved to do. If fish stocks are declining, the fault lies with pollution, over-abstraction, habitat destruction, and climate change — not with a protected bird. Shooting cormorants is a temporary band-aid that ignores the real problems. Habitat restoration is the only sustainable answer. Anyone who disagrees is either scientifically illiterate or motivated by bloodlust.
This position is advocated by some of the most influential voices in British wildlife, including the RSPB (the UK's largest nature conservation charity), the Wildlife Trusts, and BirdLife International. It is well-funded, highly visible, and emotionally compelling.
And parts of it are correct. Parts of it are dangerously incomplete.
Their Key Arguments — Presented Fairly
The Vacuum Effect: Shooting cormorants at a specific site creates a vacancy. Because the food source remains, new birds fly in to replace those removed. In Bavaria in 1996/97, over 6,000 cormorants were shot; within a year, numbers had returned to pre-cull levels. The RSPB cites this as evidence that lethal control is fundamentally ineffective.
Scapegoating: Conservationists argue that blaming cormorants distracts from the real drivers of fish decline — agricultural runoff, raw sewage, water company abstraction, and destroyed spawning habitat. These are human-made crises. The cormorant is merely a convenient scapegoat.
Artificial Buffets: Many affected fisheries are artificially stocked. To a cormorant, a densely stocked commercial lake is an undefended food source. Blaming the predator for exploiting an unnatural setup is ecologically backwards.
Habitat as Solution: Fish refuges, woody debris, bankside planting, and reed beds all make it harder for cormorants to hunt efficiently. Fix the habitat, and the predator-prey balance will naturally stabilise. No shotgun required.
Indiscriminate culling of Cormorants will not solve local conflicts or protect fish stocks, and would set a dangerous precedent for wildlife conservation. Abundant wildlife is an essential part of healthy ecosystems, and cormorants have as much right to eat fish as we do.
There is no proof that killing is more effective at reducing the number of cormorants than simply scaring them. Regular human disturbance was found to be consistently effective in reducing bird numbers.
We respect these organisations. We respect the people behind them. We respect their right to hold and promote these views. What we do not accept is that these views should go unchallenged by evidence simply because the people holding them have large platforms and good intentions.
And one argument in particular demands an immediate challenge.
The "Artificial Buffet" Myth
The suggestion that cormorant predation is primarily a problem at artificially stocked commercial fisheries — and therefore somehow self-inflicted — is perhaps the most damaging misconception in this entire debate. It is flatly contradicted by the evidence.
The most devastating cormorant impacts in the scientific literature are on natural rivers and wild fish populations. In Denmark, PIT-tagging studies on natural lowland rivers found that 30% of wild brown trout and 72% of wild grayling were consumed by cormorants. On a medium-sized river, 79% of radio-tagged adult grayling were removed in a single winter. The researchers concluded that cormorant predation "appears to be at a level that explains the observed collapse of grayling and brown trout populations" in Danish streams.
In England, the Hampshire Avon — one of the finest chalk streams on Earth, a natural river system of international conservation significance — saw its world-class wild roach fishery collapse as cormorant numbers increased. The Environment Agency's own fish stock surveys on the Chelmer, Stour, and other natural rivers show the same pattern: good juvenile recruitment, then catastrophic survival failure once fish reach the size range vulnerable to avian predation.
Atlantic salmon smolts — wild fish migrating through natural river systems — lose an estimated 40–60% to predation as they navigate downstream to the sea. These are not stocked fish in commercial ponds. These are endangered wild salmonids in rivers with SSSI and SAC designation, protected under the Habitats Directive.
The majority of the fishery managers, river keepers, and angling clubs who contact Hydroscape are managing natural waters. They are not running commercial day-ticket operations. They are custodians of wild river systems, and they are watching those systems collapse. Telling them their problem is self-inflicted is not just wrong — it is an insult to the ecosystems they are trying to protect.
Sources: Jepsen, N. et al. (2018). Change of foraging behaviour of cormorants and the effect on river fish. Hydrobiologia, Springer; Jepsen, N. et al. (2019). Impact of cormorant predation on Atlantic salmon and sea trout smolt survival. Fisheries Management and Ecology; Environment Agency fish stock survey data (various catchments); Atlantic Salmon Trust — smolt predation evidence
The Assumption That Must Be Challenged
The entire conservation argument rests on an assumption that is almost never stated explicitly: that the people asking for A06 licences aren't already doing the other things. That they aren't planting bankside cover. That they aren't installing fish refuges. That they aren't improving water quality. That they aren't recording biodiversity. That they're reaching for a shotgun because they can't be bothered to do anything else.
This assumption is patronising, inaccurate, and insulting to the thousands of fishery managers, angling clubs, and conservation-minded land managers who spend tens of thousands of pounds and hundreds of hours each year on habitat improvement — and still lose their fish stocks to predation that exceeds the rate of natural recruitment.
The Rate of Recruitment Problem
Here is the arithmetic that the conservation lobby refuses to engage with. A single cormorant consumes a minimum of 500g of fish per day. During the breeding season, when feeding chicks, this rises to between 1.1kg and 1.9kg per day, with chicks themselves requiring up to 632g per day at peak growth.
The overwintering cormorant population in England is estimated at between 24,758 (Defra's improved methodology, 2010/11) and 65,000+ (Natural England's own internal guidance, 2024). Even taking the lower, oldest, government-accepted figure — which Defra themselves noted was already 20% lower than the previous estimate — the arithmetic is stark: 24,758 birds × 500g/day × 213 days (1 Sep – 15 Apr) = 2,636 tonnes of fish. Using Natural England's own 65,000 figure, it exceeds 6,900 tonnes. And these calculations use only the minimum daily consumption of 500g — not the 1.1–1.9kg consumed during chick-rearing, and not the fish that are attacked, wounded, and left to die without being consumed.
We present this arithmetic not as a definitive figure, but as a conservative lower bound that almost certainly underrepresents the true scale of extraction. The real number is higher — potentially significantly higher. But even this floor figure makes the point: no amount of bankside planting replaces thousands of tonnes of fish. Habitat restoration improves the rate of recruitment — the speed at which fish populations replenish themselves. But if the rate of predation exceeds the rate of recruitment, the population declines regardless of habitat quality. This is not opinion. This is ecology.
Sources: Daily consumption — Grémillet et al. (2012); Chick requirements — Netherlands study cited in Angling Trust Impact Report; Population — JNCC/WeBS indices 2024, Defra Fish-eating Birds Review 2013
An Analogy
Imagine your bath is overflowing. The conservation position says: turn the tap on harder (improve habitat to increase fish recruitment). This is sensible advice. But it's incomplete — because the plug is out. The water is draining faster than it's filling. You can turn the tap to maximum and the bath will still empty. At some point, you also need to put the plug back in — which means managing the rate of extraction. Responsible management isn't choosing between the tap and the plug. It's doing both.
The Cumulative Pressure Problem
Here is the part of the conservation argument that its advocates haven't thought through to its logical conclusion. They are correct that fish stocks face multiple pressures: pollution, over-abstraction, habitat destruction, climate change, barriers to migration, and invasive species. WildFish (formerly Salmon & Trout Conservation) notes that these threats often act together, and The Rivers Trust acknowledges that even minor pressures can have significant impacts when considered cumulatively.
But if you accept that fish recruitment is already suppressed by pollution, abstraction, and habitat loss — and the evidence overwhelmingly says it is — then the arithmetic becomes even more devastating, not less. Cormorant predation doesn't exist in a vacuum. It operates on top of every other pressure. A fish population that might sustain natural predation levels under ideal conditions cannot sustain them when recruitment is simultaneously being hammered by sewage, low water levels, and degraded spawning habitat.
This is the argument the conservation lobby has accidentally made for us. Every factor they cite as a reason not to manage cormorants is actually a reason why management is more urgent. If the tap is already running slowly — if recruitment is already impaired by all the pressures they correctly identify — then removing thousands of tonnes of fish per winter (and that's using the most conservative estimate imaginable) is not a sustainable background pressure. It is the stressor that tips an already compromised system over the edge.
Responsible fishery managers understand this. They campaign for cleaner water, they oppose over-abstraction, they restore spawning habitat, they remove barriers to migration — and they also need to manage the predation rate, precisely because all those other problems make the fish population less resilient to it. The suggestion that you must choose one or the other is a false binary. The ecology demands both.
And let's be clear about something: acknowledging that many of these pressures are human-made does not oblige us to stand back and accept the consequences as some form of ecological penance. This is not a mea culpa situation. Yes, we polluted rivers. Yes, we over-abstracted. Yes, we built weirs and destroyed spawning habitat. The answer to that is not to wring our hands, accept our guilt, and watch fish populations collapse as a form of self-flagellation. The fish didn't cause these problems. They shouldn't be expected to absorb them.
Humans are the custodians of this planet — and that comes with responsibility. Real responsibility. Not the comfortable kind that lets you post about biodiversity on social media while opposing every practical measure to protect it. The kind that requires difficult, unglamorous, sometimes unpopular decisions. Habitat restoration is one of those decisions. Pollution reduction is another. And yes, proportionate management of a predator whose population has grown beyond what compromised ecosystems can sustain — that is also custodianship. It isn't always the convenient route. It isn't always the nicest. But it is the honest one.
Sources: WildFish — Britain's Freshwater Fish at Risk of Extinction (2025); The Rivers Trust — Habitat Loss; Brink et al. — Loss of Biodiversity in Aquatic Ecosystems (Springer); Brander, K. — Impacts of climate change on fisheries, Journal of Marine Systems (2010)
The Damage You Don't See
The tonnage figures above — conservative as they are — only count fish that are consumed. They don't account for the secondary and tertiary impacts of predation: the fish that are attacked and left wounded, the fish that change their behaviour to avoid predation, or the fish whose physiological stress response compromises their health, growth, and reproduction. The peer-reviewed science on these indirect impacts is clear, and it paints a picture that makes the consumption figures look like the least of the problem.
Measurable Stress, Measurable Consequences
Kortan and Adámek (2011) published a peer-reviewed study in Aquaculture Research measuring the physiological stress response of carp pond stock to cormorant hunting activity. They found that both the spleen somatic index and Fulton's condition coefficient — standard indicators of fish health — decreased significantly in fish subjected to cormorant predation pressure. The stress levels recorded were statistically equivalent to those caused by pond harvesting — one of the most acutely stressful events a farmed fish can experience.
In a companion study, Kortan and Adámek (2010) measured the behavioural response of carp to arriving cormorant flocks across four Czech ponds. Fish density in the littoral zones increased by a factor of several hundred after cormorant arrival — fish abandoned open water and crowded into the margins. This wasn't a gradual shift. It was a statistically significant (P<0.001) panic response recorded on every pond studied.
Sources: Kortan, J. & Adámek, Z. (2011). Stress responses of carp pond fish stock upon hunting activities of the great cormorant. Aquaculture Research; Kortan, J. & Adámek, Z. (2010). Behavioural response of carp pond stock upon occurrence of hunting great cormorant flocks. Aquaculture International, Springer
Stress, Disease, and the Cascade Effect
What happens to fish that are chronically stressed, crowded into margins, and forced to abandon normal feeding and spawning behaviours? The same thing that happens to any animal under sustained predation pressure: their immune systems weaken, their growth rates decline, and their reproductive success drops. Stressed fish are more susceptible to bacterial and viral infections. Wounded fish — slashed by cormorant beaks but not consumed — develop secondary infections that can spread through a population.
Cormorants are also known to actively hunt prey much larger than they can eat, inflicting deep lacerations with their hooked beaks before abandoning the fish. These wounded fish don't appear in any consumption calculation. They die slowly, often days later, from infection or stress. They are invisible in the data — but they are very real in the water.
Fish displaced from their normal habitats stop feeding efficiently, abandon established territories, and — critically — leave spawning sites. A fish that survives predation but fails to spawn has been functionally removed from the breeding population. The recruitment rate drops not just because fish are being eaten, but because the surviving fish are too stressed, too displaced, and too compromised to reproduce effectively.
This cascade — predation, wounding, stress, displacement, disease, reproductive failure — means that the true impact of cormorant presence on a fishery is multiples of the consumption figure alone. These secondary and tertiary impacts — the stress, the disease, the behavioural disruption, the lost spawning — are largely unmeasured, entirely uncounted in the official data, and almost never discussed by the organisations opposing management. The real cost is systemic, behavioural, and invisible in the arithmetic.
Sources: USDA APHIS — Preventing and Managing Cormorant Damage (2025); Kortan, J. et al. (2008). Indirect manifestation of cormorant predation on pond fish stock. Knowledge and Management of Aquatic Ecosystems; Adámek, Z. et al. (2007). Computer-assisted image analysis in evaluation of fish wounding by cormorant attacks. Aquaculture International
The Numbers We're Told
UK cormorant population data comes primarily from the Wetland Bird Survey (WeBS), a partnership between the BTO, RSPB, and JNCC, with fieldwork conducted by volunteers. The JNCC's own published methodology states clearly that WeBS data are not a population estimate, but are an index of population size with unknown bias.
This is crucial. An index is not a count. It's a statistical model that infers population size from sample observations at a subset of sites. The early years of the dataset (pre-1990) are acknowledged to have suffered from under-recording. The BTO itself has performed data validation exercises that resulted in revised (lower) estimates — Defra's 2013 review noted that the improved methodology found approximately 20% fewer cormorants in England than previously thought.
The 25-year trend shows a 66% increase. The 10-year trend shows a 26% increase. But these figures describe the index, not the actual population. They measure observed birds at monitored sites. They do not measure cormorants at unmonitored sites, in transit, feeding at dawn or dusk outside survey windows, or dispersed across the thousands of small fisheries, farm ponds, and ditches that WeBS doesn't cover.
Sources: JNCC Cormorant Indices; Defra Fish-eating Birds Review 2013; PMC/NIH: Managing wildlife populations with uncertainty (2008)
The Question Nobody Asks
If the accepted population data is an index with unknown bias, derived from volunteer counts at a subset of sites, with acknowledged under-recording in early years — why is it treated as settled science by the organisations opposing management? And if the data is uncertain, shouldn't that uncertainty increase the case for precautionary management, not decrease it?
Even accepting the official figures at face value: a 66% increase over 25 years, from an already elevated post-1981 baseline (when cormorants were removed from the general shooting licence), is not a population that is "stabilising." It is a population that grew explosively and has now levelled off at a plateau that inland fisheries cannot sustain.
Freedom of Information: EIR2026/01073
In January 2026, a Freedom of Information request was submitted to Natural England asking for the documents they use when deciding and assessing cormorant licence applications. The response, received in March 2026, included seven internal guidance documents totalling over 100 pages — documents that reveal how the licensing system actually works from the inside.
What these documents contain is remarkable — not because they expose wrongdoing, but because they confirm, in Natural England's own words, several things that the conservation lobby either denies or ignores.
It is accepted that proving damage by direct evidence alone is extremely difficult in many circumstances. If, on balance, it is reasonable to assume from indirect or circumstantial evidence that cormorants are causing serious damage at a site then this should be taken as basis for serious damage occurring.
Read that again. Natural England themselves acknowledge that proving cormorant damage by direct evidence alone is "extremely difficult." They instruct their own officers to accept indirect and circumstantial evidence as sufficient basis. And yet the conservation lobby continues to argue that because direct evidence of population-level damage is limited, management is unjustified. They are holding fisheries to an evidence standard that the regulator itself recognises as unrealistic.
WeBS counts are used to provide trends in bird numbers, not population sizes or estimates and using these as likely maxima for an area is unsound.
This is Natural England — the government body responsible for cormorant licensing — explicitly stating in their own internal guidance that using WeBS data as population estimates is "unsound." This is the same WeBS data that the RSPB, BTO, and JNCC use as the basis for claiming the cormorant population is "stable" or "levelling off." The regulator's own internal documents contradict the data foundation on which the entire anti-management argument rests.
The Numbers Behind the Curtain
The FOI documents also reveal the precise mechanics of the licensing threshold. APHA (Animal and Plant Health Agency) modelling concluded that a maximum of 2,687 cormorants can be shot annually in England to maintain a stable population — with a 50:50 chance of either maintaining sustainability or causing detrimental impact at that level. This threshold was exceeded in 2018/19, when 2,699 birds were shot.
The internal guidance notes that Natural England's wintering cormorant population is "normally around 65,000 birds" — significantly higher than the WeBS-derived index figures often cited publicly. The documents confirm that in 2022-23, 80% of the permitted maximum was actually shot, and that 2023-24 data remained incomplete as of August 2024 with only 1,806 birds recorded.
Perhaps most tellingly: in 2023/24, 13 licensees did not renew their applications, and only 32 new applications were received (as of August 2024). For a problem affecting thousands of fisheries nationwide, these numbers are vanishingly small — and they represent the entirety of the data that Natural England uses to assess whether the problem is severe enough to warrant policy change.
Source: Natural England EIR2026/01073 — Cormorant Generic Licence Assessment (August 2024); Internal Guidance Note SD/IGN/2017/007 (valid to April 2026). All quoted text is Natural England copyright, re-used under the terms of the FOI response for the purposes of criticism and review, in accordance with the Copyright, Designs and Patents Act 1988.
The Application Gap
32 new applications in a year. For all of England. For a predation problem that affects virtually every inland fishery, every chalk stream, every club water, and every stocked lake in the country. The reason the national cap hasn't changed isn't that the problem isn't severe. It's that the evidence pipeline is almost empty. Applications fail because the paperwork doesn't meet the five licensing tests. Fisheries don't apply because they don't know the process exists, don't know what evidence is required, or can't compile it in the format Natural England demands.
This is exactly the gap Hydroscape exists to close.
Why Bavaria Is Only Half the Story
The Bavaria example — 6,000 birds shot in 1996/97, numbers returning within a year — is cited constantly by the RSPB, BirdLife, and conservationists as proof that culling "doesn't work." It has become the single most powerful talking point in the anti-management arsenal.
But the lesson from Bavaria isn't that management is pointless. It's that uncoordinated, data-poor management is pointless. A regional shoot without structured evidence, without ongoing monitoring, and without integration with habitat management and deterrent strategies will fail — because it's treating the symptom in isolation.
This is precisely why the A06 licensing system exists — and precisely why it needs to work better. Every A06 application that is approved, reported on, and renewed generates data. That data, aggregated nationally, builds the evidence base that Natural England and Defra use to set policy. If the pipeline of applications is strong, structured, and undeniable, the case for reviewing the national cap — or for broader coordinated management — becomes impossible to ignore.
That's what Hydroscape is building: a streamlined, data-rich pipeline that makes the A06 application process realistic and achievable for every fishery in England. Not because we want to replicate Bavaria's mistakes, but because we want to make the evidence so comprehensive that the policy response has to match the scale of the problem.
The Easiest Position to Defend
There is a reason the "habitat only, no killing" position is so popular among mainstream conservation organisations. It is the easiest position to defend. It costs nothing to advocate for. It requires no difficult trade-offs. It positions the advocate as morally superior by default — because who could argue against "not killing things"?
This is not conservation. It is performance. Real conservation requires making uncomfortable decisions based on evidence. It requires acknowledging that ecosystems are not static, that populations fluctuate, that human intervention created the current imbalance, and that human management is sometimes necessary to correct it. Chris Packham himself has acknowledged this principle — in the context of deer.
Overgrazing by deer is driving the decline in nightingales. Since we have no large predators — no lynx, no wolf, no bear — we have no choice in the UK but to manage our deer population otherwise we'll lose nightingales. Scientifically informed culling is unfortunately an artefact of our lives. If we want to preserve a rich mosaic of species and habitats, we have to accept that.
We agree completely. Scientifically informed culling is unfortunately an artefact of our lives. The question is why this principle applies to deer damaging nightingale habitat, but not to cormorants damaging fish populations. The logic is identical. The ecology is identical. The only difference is that one position is popular with the conservation establishment and the other is not.
When your position changes depending on which species is involved rather than the underlying ecological principle, you are not practising conservation. You are practising species favouritism. And species favouritism is not science.
A Decade of Slow Progress
Government-funded Fishery Management Advisors have been in place since 2014, dealing with over 1,000 enquiries per year on cormorant, goosander, otter, and seal predation. Area-based licensing was introduced. The national cap was raised from 2,000 to 3,000 birds.
And yet, after more than a decade of this infrastructure: the campaign to add cormorants to the general licence was rejected. The national cap has not increased beyond 3,000. The evidence requirements for goosander control are so high that applications are routinely refused. Natural England applies five rigorous tests to every A06 application, and applications that fail to present structured, evidenced data are rejected — not because the problem isn't real, but because the paperwork doesn't prove it.
This is the gap that matters most. Fisheries are suffering genuine, measurable predation damage — but their applications fail because the evidence isn't formatted, structured, or comprehensive enough to meet Natural England's threshold. The problem is not a lack of damage. It is a lack of data infrastructure.
And the number of fishery managers who contact us — in our first few weeks of operation — who had no idea they could already apply for an A06 licence is staggering. Something isn't reaching the people who need it.
This Is Exactly What Hydroscape Solves
Our A06 Master Builder compiles timestamped sighting records, GPS-tagged photographic evidence, structured deterrent logs, and biodiversity data into a single, formatted application — built to meet Natural England's five tests from the ground up. The data is AI-verified, independently reproducible, and presented in a format that cannot be dismissed as anecdotal.
We don't charge for this. We don't require membership. We don't sit on project boards with the organisations we're supposed to be challenging. Our only stakeholder is the fishery manager standing at the water's edge watching their stock disappear — and our only objective is making sure their evidence is strong enough that it cannot be refused.
The Integrated Approach
Real conservation is not a single action. It is not "habitat only" or "shooting only." It is the intelligent integration of every available tool, deployed based on evidence, measured for effectiveness, and adjusted over time. This is what Hydroscape-Group exists to enable:
Every sighting report submitted through Hydroscape is timestamped, GPS-tagged, and structured to Natural England's evidence requirements. Where photographs are attached, they are AI-analysed for species confirmation, automatic bird counts, and subspecies indicators. Every deterrent action is logged with method, duration, and effectiveness rating. Every wildlife observation is recorded alongside the cormorant data, building a picture of the whole ecosystem — not just the species that generates headlines.
This is what the debate is missing. Not more opinions. Not more campaigns. Not more lobbying. More data. Better data. Data that can't be dismissed as anecdotal, because it's structured, verified, and independently reproducible.
Our platform scores 9.9/10 on the OWASP Top 10:2025 security framework — the highest in the UK wildlife and conservation sector, independently verified by SecurityHeaders.com. Our data integrity is not a talking point. It is an auditable, reproducible fact.
Beyond Cormorants — HydroTasks
If we only built tools for cormorant reporting, you could reasonably ask whether we're just the other side of the same coin. We're not. HydroTasks is our free outdoor task management platform — a satellite map-based PWA for fisheries, farms, estates, and conservation sites. It's used daily for habitat improvement planning, seasonal calendar management, hazard mapping, site feature recording, and formal risk assessments with residual risk scoring and PDF export.
That means the same fisheries using Hydroscape to record cormorant sightings are also using HydroTasks to plan bankside planting, schedule weed bed restoration, map fish refuges, log habitat improvements, and manage their sites holistically. The suggestion that licence applicants aren't doing the wider environmental work is not just patronising — in many cases, we can prove it's wrong, because we built the tools they're using to do it.
Our Position — Clearly Stated
Hydroscape-Group believes in responsible, evidence-based management of all species — including cormorants. We believe in habitat restoration. We champion biodiversity recording. We provide tools for non-lethal deterrence. We also believe that when predation demonstrably exceeds the rate of recruitment — when the evidence shows that a fishery is losing more fish than its ecosystem can replace — then proportionate, licensed lethal control is a legitimate, legal, and ecologically sound management tool.
We believe this not because we want to kill birds, but because we understand symbiotic relationships and the need for balance. We believe that positioning yourself by default as the group that opposes all lethal control is not moral courage — it is the avoidance of difficult decisions. And avoiding difficult decisions is not conservation. It is abdication.
3,000 — And Why It Won't Change Without You
The national cap on cormorants that can be taken under A06 licences in England is 3,000 birds per year. Campaigns to add cormorants to the general licence — which would allow proportionate control without individual applications — have been repeatedly rejected by government.
That cap is set based on the data available to Natural England and Defra. If fisheries don't apply for licences, the data says the problem isn't severe. If the data says the problem isn't severe, there is no justification for changing the cap. Every licence that isn't applied for is a data point that doesn't exist.
This is why we provide the A06 Master Builder — a dedicated tool that compiles your sighting records, deterrent logs, photographic evidence, and biodiversity data into a structured licence application formatted for Natural England. Completely free. Because the barrier to applying should be the evidence threshold, not paperwork.
Your Application Is a Vote
Even if your individual licence permits the taking of 5 birds, your application itself is a vote. It tells the system that cormorant predation is causing serious damage at a real site, backed by real evidence. The more fisheries that apply with strong, structured data, the stronger the case becomes for reviewing the national cap. Not applying means not being counted. Silence is interpreted as satisfaction.
Don't invest in feelings.
Invest in facts.
Because feelings won't pay you back.
The cormorant debate will not be resolved by celebrity campaigns, social media outrage, or emotional appeals. It will be resolved by data. Structured, verified, independently reproducible data — collected at the waterside by the people who actually manage these environments every day.
That's what we build. That's what we provide. Completely free.
And if you disagree with us — or we've quoted you — then we want to hear from you the most. Get in touch, because we'd love to talk, share ideas, and reach the best conclusions for a balanced, sustainable ecology for all.
From Predation to Protection — A06 Licence Guide
Our step-by-step guide to obtaining your Natural England A06 licence, with free tools at every stage. Read the guide →
Know Your Cormorant — Subspecies Guide
Understanding the difference between P. c. carbo and P. c. sinensis — and why it matters for management. Read the guide →
HydroLibrary — 497 Species
Habitat management ideas, species identification, and conservation status for the species that share your water. Explore HydroLibrary →
Population Data: JNCC Provisional Cormorant Population Indices for England (2024 update); Defra Fish-eating Birds Policy Review Evidence Summary (2013); BTO Cormorant Species Page; WeBS Official Statistics (2025).
Predation Research: Grémillet, D. et al. (2012). Fish are not safe from great cormorants in turbid water. Aquatic Biology, 15; Stewart et al. (2005). Cormorant predation at Loch Leven. Journal of Zoology, 267(2); Ovegård et al. (2021). Cormorant predation effects on fish populations: a global meta-analysis. Fish and Fisheries; Skov, C. et al. (2013). Cormorant predation on PIT-tagged lake fish. Journal of Limnology, 73.
Population Modelling: PMC/NIH — Managing wildlife populations with uncertainty: cormorants Phalacrocorax carbo (2008); Chamberlain et al. — no detectable effect of shooting on population trends (cited in BTO).
Conservation Positions: BirdLife International (2025) — Culling Cormorants won't save fish; RSPB Position Statement on Cormorants; Chris Packham — cited in BBC Springwatch, Born Free interview (2025), Fly Fishing Forum archive.
Policy & Licensing: Natural England — Fish-eating birds: licence to protect your fishery (A06 and A07), GOV.UK (2025); Defra GL42 General Licence (2026); Parliamentary Research Briefing SN06412 — Cormorants and fisheries.
Bavaria Study: RSPB Press Release (1997), cited in BirdForum archive and Parliamentary Briefing.
Methodology: WeBS — BTO/RSPB/JNCC partnership. JNCC states: "WeBS data are not a population estimate, but are an index of population size with unknown bias."
FOI Data: Natural England EIR2026/01073 (March 2026) — 7 internal guidance documents including: Cormorant Generic Licence Assessment (August 2024, 7 pages); Internal Guidance Note SD/IGN/2017/007 — Piscivorous Bird Licensing (35 pages, valid to April 2026); Technical Assessment Form; DTC Renewal Assessment Form; Renewal Assessment Form; DTC Renewal Desk Instructions (43 pages); HPAI Disease Risk Assessment Desk Instructions. All documents marked "INTERNAL USE ONLY" and released under EIR.