Impact of Poor Fishery Management on Marine Resources

The scale of the destruction is simply unimaginable. The Annelies Ilena - which I've discussed before - is a giant factory ship that can capture 400,000 kilograms of fish in a single day. It's a giant death factory. But that's not all, supertrawlers have a much bigger impact. 1. Overfishing and Ecosystem Collapse Super trawlers and bottom trawlers contribute to the overexploitation of fish stocks, depleting populations faster than they can recover. The Bay of Bengal study found that increasing trawler activity leads to habitat destruction and threatens the entire marine food pyramid, including top predators. 2. Bycatch and Marine Biodiversity Loss Trawling is highly non-selective, capturing and killing many non-target species (e.g., sea turtles, dolphins, sharks). A review on trawling and bycatch highlighted that endangered species often fall victim to these nets, and that bycatch reduction devices are not widely used. 3. Habitat Destruction and Seafloor Damage Bottom trawling scrapes the ocean floor, causing irreversible damage to benthic ecosystems. Studies on seabed trawling found that it flattens marine habitats, reducing biodiversity by eliminating slow-growing species like corals and shellfish. Trawling in the Mediterranean (Gioia Canyon) led to the destruction of vulnerable marine ecosystems like deep-sea coral forests. 4. Changes in Seafloor Chemistry and Ocean Health Trawling disturbs the seabed’s natural biogeochemistry, affecting nutrient cycles and oxygen levels. A study in the North Sea found that repeated trawling leads to long-term disruptions in nutrient cycling, causing habitat degradation. 5. Impact on Seabirds and Marine Mammals Seabirds alter their natural foraging behaviours due to fishery discards from trawlers, increasing their dependence on human activities. A study in the Mediterranean found that seabirds’ movement patterns were significantly altered when trawlers were active, affecting their long-term survival. 6. The Scale of Trawling’s Impact Studies estimate that bottom trawlers disturb up to 15 million square kilometres of seabed annually - an area 150 times greater than global deforestation. 7. What Can We Do? - More protected marine areas, which when enforced (many of them aren't!), can help ecosystems recover. - Introduce stricter fishing quotas. - Change behaviours so people eat a LOT less fish. Image via Leon Simons SOURCES: - Trawling's a Drag for Marine Life (Malakoff, 2002). - Environmental Impact of Trawling in the Bay of Bengal (Das, 2018). - Trawling and By-catch: Implications on Marine Ecosystems (Kumar & Deepthi, 2006). - Fishery Discards and Seabird Movement Patterns (Bartumeus et al., 2010). - Impact of Trawl Fisheries on Marine Benthic Biogeochemistry (Percival, 2004). - Effects of Trawling on Coral and Sea Pens (Pierdomenico et al., 2018). - Assessing and Mitigating Bottom Trawling Impacts (Rijnsdorp et al., 2017).

The use of bottom trawling in the fisheries industry is hugely controversial due to the detrimental impacts to the seabed, and other unintended consequences to aquatic biodiversity. Bottom trawling is responsible for a quarter of all global catch every year and 32% of total catch within the EU (7.3 million tonnes), more than any other fishing technique. Eight of the top ten countries that emit the most carbon emissions through bottom trawling are in Europe (UK, Italy, Denmark, France, the Netherlands, Norway, Croatia and Spain). The other two are China and Russia. Revive Our Ocean, a global initiative that seeks to scale marine conservation efforts to boost ocean health and secure the future of the coastal communities and marine biodiversity, are campaigning for the end of bottom trawling in Marine Protected Areas (MPAs). Bottom trawling is banned in many areas of EU waters since 2006, when it adopted a regulation to ban fishing practices deemed likely to damage marine habitats. It specifically bans bottom trawling in all MPAs that host certain vulnerable habitats such as #seagrass meadows and #coralreefs. The European Commission once defined bottom trawling as one of "the most widespread and damaging activities to the seabed and its associated habitats.” However, the practice is still permitted in over 80% of MPAs in Europe and nearly all in the United Kingdom. Less than 3% of global oceans are effectively shielded from damaging fishing practices like bottom trawling. Bottom trawling involves one or two boats dragging large weighted nets across the seabed. Trawling aims to catch species that live on or close to the seafloor such as cod, hake, shrimp, octopus, and anglerfish. This method also captures a lot of unwanted or non-target fish that are unintentionally caught, which can make up to 60% of the total catches. Unwanted fish and endangered animals such as dolphins, sea turtles, and sharks, get captured in the nets, getting badly injured or killed, and are then thrown back to the sea. Trawling causes significant damage to coral reefs and seagrass meadows, one of the ecosystems that absorbs the most carbon (circa. 35 times faster than tropical rainforests). By damaging the ecosystems on the seabed and harming marine life with bottom trawls, the fishing industry is effectively removing one of the most important natural #climatemitigation tools we have against the #climatecrisis, while contributing to a decline in biodiversity. Protecting the oceans and the biodiversity supported by aquatic ecosystems across the planet are vital for tackling the effects of human-induced #climatechange. A healthy ocean is essential for keeping our climate balanced and protect the habitats and wildlife that lives in the world's oceans throughout the planet. The planet's oceans are of paramount importance to human life, covering more than 70% of the planet and producing at least 50% of earth’s oxygen. Image credit: National Geographic

With overcapacity in catching power, weak fisheries legislation, the chronic damage of bottom trawling, and virtually no meaningful marine protected areas, the twin impacts of ocean warming and deoxygenated seas now combine to create a perilous future for fisheries and global food supply. A major new study reported by The Guardian finds that chronic ocean heating is driving “staggering” losses of marine life, with fish populations declining sharply as seabed temperatures rise. This is happening now. Climate change is no longer an added pressure. It is a threat multiplier, accelerating the damage caused by decades of poor ocean governance and over-exploitation. Billions of people depend on the ocean for protein and livelihoods. When marine ecosystems weaken, food security weakens. Economic security weakens. Social stability weakens. Actions required are predictable: *Rapid emissions reduction *Stronger, enforceable fisheries management *Meaningful, well-connected marine protected areas *An end to the most destructive fishing practices Chronic warming isn’t just heating the ocean. It is quietly dismantling the life-support system that sustains us and driving deteriorating weather patterns we are all experiencing including where I live, non stop rain! #BlueHeart #OceanHealth #ClimateAction #FoodSecurity #Fisheries #Biodiversity #MarineProtection #Sustainability #ClimateCrisis Chronic ocean heating fuels ‘staggering’ loss of marine life, study finds https://lnkd.in/eWfjXUbi

When Are We Going to Talk About It? Beneath the ocean’s surface, a silent transformation is happening. Coral structures that took centuries to grow are shattered in minutes. Seagrass meadows—critical nurseries for marine biodiversity—are erased. Ancient seabeds, shaped by natural processes over millennia, are flattened in a single tow. This is the hidden footprint of bottom trawling. While it remains one of the most efficient fishing techniques for large-scale harvest, it is also among the most disruptive disturbances ever imposed on benthic ecosystems. Massive weighted nets dragged across the seabed do not discriminate. Along with target species, they capture juvenile fish, sharks, turtles, and countless non-target organisms—most of which are discarded. The real issue is not only what is removed from the ocean. It is what is irreversibly altered. Seafloor habitats are not empty landscapes; they are complex ecological infrastructures supporting fisheries productivity, carbon storage, and coastal resilience. When these systems collapse, recovery is measured not in seasons—but in decades, sometimes centuries. Today, technology gives us unprecedented visibility into what happens below the surface: subsea observation platforms, environmental sensors, AI-driven monitoring, and advanced marine mapping tools. The science is clearer than ever. The question is no longer whether we know. The question is when we decide to act on what we know. Because protecting marine ecosystems is not only an environmental responsibility—it is a matter of long-term food security, economic sustainability, and planetary stability. Perhaps the real question remains: When are we going to talk about it seriously? 🌊 #Marine #Science #FisheriesManagement #OceanSustainability #MarineEcosystems #BlueEconomy #OceanProtection #EnvironmentalGovernance

I grew up in Helvick, immersed in the fishing industry, and I’ve always been proud to call myself a fisherman. However, what’s happening in the Irish fishing industry is nothing short of appalling. A massive foreign fleet is now taking over 85% of the fish caught in our waters, while a handful of industrial trawlers are devastating our bays. Vessels from outside the EU, including those from Norway and Iceland, are plundering our rich marine resources. I’ve tirelessly advocated for sustainability to be at the forefront of our industry, but it’s truly heartbreaking 💔 to see large Irish trawlers contributing to the decline of our inshore waters. We are witnessing a complete collapse of our inshore ecosystems, yet there are still calls to increase our fishing quotas. Just thirty years ago, a 38-foot vessel from Helvick could easily catch 100 boxes of fish a day—whiting, prawns, sole, brill, plaice, and other prized species. Today, that same boat would be lucky to catch three boxes. Brill, sole, turbot, and plaice are now nearly nonexistent. Whiting and many other fish species have been decimated, primarily due to industrial fishing practices in our bays. These fish populations could recover if we put an end to industrial fishing. The entire inshore fishing community stands united against this destruction. In the past week alone, I’ve received hundreds of messages and calls of support regarding my stance on industrial fishing. Most fishermen are passionate environmentalists who wholeheartedly believe in sustainability. Yet, a small number of boats are jeopardizing the future of our entire fishing industry. The harvesting of juvenile fish does not represent the true spirit of Irish fishing. Nearly all fishermen oppose these practices. We must protect our inshore waters for the sake of the inshore fleet and the future of our marine environment.

Overfishing Isn’t Just About Fish 🐟🐠 It’s About System Collapse🎣⛴️ Overfishing isn’t just about catching too many fish. It’s about destabilizing entire ocean systems. When fishing pressure exceeds nature’s ability to recover: • food webs collapse • predator–prey balance breaks • smaller, weaker fish dominate populations • biodiversity declines • coastal communities become more vulnerable This isn’t only an environmental issue it’s an economic, food security, and sustainability crisis. We often talk about overfishing as if it’s a distant problem. But in reality, it affects: • seafood prices • fisher livelihoods • ecosystem resilience • the future of global protein supply The uncomfortable truth? If we treat fish stocks as infinite, we’ll eventually run out of both fish and options. Marine science plays a critical role here not just in measuring fish populations, but in shaping fisheries policies, management strategies, and recovery plans. Because sustainable fishing isn’t about stopping fishing. It’s about fishing smarter before the system breaks. 💬 Do you think stricter fishing regulations help or hurt fishing communities in the long run? #MarineScience #Overfishing #FisheriesManagement #OceanSustainability #BlueEconomy #SeafoodIndustry #MarineEcosystems #EnvironmentalPolicy