Fishing And Climate Change

The world’s oceans are a crucial component of our planet’s ecosystem, providing habitat for countless species and playing a significant role in regulating the global climate. However, certain fishing methods have been found to have adverse effects on the environment and contribute to climate change.

In this blog post, we will explore the impacts of specific fishing techniques and emphasize the need for sustainable practices to protect our oceans and mitigate climate change.

Bottom Trawling

Bottom trawling is a fishing method that involves dragging large nets along the ocean floor to catch fish and other marine organisms. Imagine a massive net, often as wide as a football field and equipped with heavy metal doors or “trawl doors,” being dragged behind a fishing vessel.

As the fishing boat moves forward, the net sweeps across the seabed, scooping up everything in its path. It indiscriminately captures not only the target species but also any other marine life that happens to be in the area, leading to significant bycatch. The net can catch fish, crustaceans, benthic organisms, and even fragile coral reefs, damaging or destroying the delicate structures that took years to form.

Bottom trawling has severe environmental consequences. This technique is known to destroy delicate marine habitats, such as coral reefs and seafloor ecosystems, which serve as carbon sinks. When these habitats are disrupted, vast amounts of carbon dioxide are released into the atmosphere, exacerbating climate change.

When it comes to the sheer amount of trawled catch, China, Vietnam, and Indonesia reign as the triumvirate of top producers.^[1] These three nations boast impressive volumes of fishing output. However, zooming in on the intensity factor, which considers the amount of trawled catch relative to the size of a country’s marine area, West African nations take center stage.

Yet, here’s the disheartening truth: up to a staggering 90% of the trawled catch in these countries is seized by foreign nations operating within their own waters. These arrangements, facilitated through trade agreements, frequently showcase glaring inequities.

Ghost Fishing

Ghost fishing occurs when abandoned, lost, or discarded fishing gear continues to trap and kill marine life. This gear, often made of non-biodegradable materials like plastic, persists in the ocean for years.

The Great Pacific Garbage Patch, now a vast expanse measuring 1.6 million square kilometers, roughly three times the size of France, holds a shocking secret. Deep within its confines, an estimated 46% of its composition is attributed to ghost nets.^[2] These discarded fishing nets, once deployed with purpose but now abandoned and entangled, contribute significantly to the patch’s expanding presence. But the impact of ghost nets extends far beyond this infamous garbage patch. They account for up to 10% of all marine litter, casting their spectral presence across the vast expanses of our oceans.

Not only does ghost fishing contribute to overfishing, but it also releases greenhouse gases as the trapped organisms decompose. Additionally, the production of fishing gear, particularly synthetic nets and lines, contributes to carbon emissions during the manufacturing process.

Overfishing

Overfishing, the excessive extraction of fish stocks beyond their sustainable levels, disrupts marine ecosystems and exacerbates climate change.

When predator populations are depleted due to overfishing, their prey populations can explode, leading to imbalanced ecosystems. For example, overfishing of large predatory fish such as sharks can result in an increase in smaller fish populations, which in turn leads to greater consumption of plankton. Since plankton absorbs carbon dioxide, this disruption can reduce the ocean’s ability to sequester carbon effectively.

Overfishing and the presence of illegal, unreported, and unregulated fishing pose significant risks to the world’s fish populations. The Southeast Pacific region stands out as the most vulnerable, with a staggering 66.7 percent of its fish stocks being classified as biologically unsustainable. Following closely are the Mediterranean Sea and the Black Sea, where 63.3 percent of fish stocks face the same threat. The Northwest Pacific region also faces substantial challenges, with 45 percent of its fish stocks in a precarious state.^[3]

As Jason Link, senior scientist for Ecosystem Management at NOAA Fisheries, says, “In simple terms, to successfully manage fisheries in an ecosystem, the rate of removal for all fish combined must be equal to or less than the rate of renewal for all those fish.”^[4]

Bycatch

Bycatch, the unintended capture of non-target species, is another pressing issue associated with certain fishing methods. It often results in the death of various marine creatures, including endangered species.

This loss of biodiversity not only disrupts ecosystems but also undermines their ability to mitigate climate change. Additionally, discarding bycatch wastes valuable resources, including energy, fuel, and labor, all of which contribute to greenhouse gas emissions throughout the fishing industry’s supply chain.

Sustainable Alternatives

Adopting sustainable fishing techniques such as selective fishing gear, can reduce bycatch. This includes using techniques like circle hooks, size-selective nets, and modified trawling gear.

Establishing Marine Protected Areas (MPAs) can help protect critical habitats and breeding grounds for fish species. By designating specific areas where fishing is restricted or prohibited, MPAs allow fish populations to replenish and ensure long-term sustainability.

Implementing regulations on fishing effort, such as catch limits and quotas, can prevent overfishing and maintain balanced fish populations. This involves setting sustainable harvest levels based on scientific assessments and monitoring catches to ensure compliance.

Promoting traceability systems and certifications, such as the Marine Stewardship Council (MSC) certification, helps consumers identify sustainably sourced seafood. These initiatives encourage responsible fishing practices and provide economic incentives for fishers to adopt sustainable methods.

Promoting responsible aquaculture practices can help reduce the pressure on wild fish stocks. Fish farming operations that prioritize sustainable feed sources, minimize habitat impacts, and ensure proper waste management contribute to a more sustainable seafood industry.

Lastly, encouraging collaboration among governments, fishers, scientists, conservation organizations, and other stakeholders is essential for effective fisheries management. By involving all relevant parties, decisions can be made collectively to ensure the long-term sustainability of fishing practices.

Conclusion

The adverse effects of certain fishing methods on climate change and the environment demand urgent attention and collective action. The examples discussed, such as bottom trawling, ghost fishing, overfishing, and bycatch, serve as poignant reminders of the intricate interconnectedness between our oceans and the global climate.

Responsible consumption plays a pivotal role in shaping a sustainable future. As consumers, we hold the power to support sustainable fishing practices by making informed choices about the seafood we consume. By opting for sustainably sourced fish, we can encourage the fishing industry to prioritize ecological balance and climate protection.

Sources: 

[1]Daniel Steadman, “Report highlights urgent need to end bottom trawling” (Phys.org, 09 December, 2021).[⇑]
[2]Sophie Hadley, “Up to a Million Tons of Ghost Fishing Nets Enter the Oceans Each Year- Study” (Earth.org, 23 November, 2020). [⇑]
[3]United Nations, Statistics Division[⇑]
[4]“New Indicators Could Help Manage Global Overfishing” (26 June, 2019).[⇑]