Biodiversity and fishing

What is biodiversity?

Biodiversity (a combination of the words ‘biological’ and ‘diversity’) is a term that refers to the variety of life on Earth. It includes all the different animals, plants and micro-organisms living on Earth and in the ocean, from tiny ants to giant whales. 

Diversity is calculated by measuring both ‘species richness’ (the number of different species in a defined area) and species composition (the relative proportions of these species). In addition, the ‘abundance’ of a population or a species (the total number of individuals) is also commonly considered when evaluating diversity changes. 

Why is marine biodiversity important?

While tropical rainforests have long been considered ‘the lungs of the planet’, far more of the planet’s oxygen (estimated 50-80%) comes from the ocean via photosynthetic marine organisms (NOAA).   

As well as contributing to the air we breathe, the ocean plays a role in stabilizing the climate. Seawater evaporates, condenses into clouds, and makes rain and snow that irrigate the land. The ocean and the biodiversity within it play key roles in capturing and storing carbon dioxide. Mangroves and kelp forests protect shorelines and coastal communities from storms and erosion.   

The ocean is central to human lives and livelihoods and provides much of the food we eat. Fish is the primary form of protein for more than a third of the global population and wild fisheries provide a livelihood for 60 million people worldwide (UN FAO).  

Marine biodiversity is essential because it allows nature to be productive, resilient, and adaptable to environmental changes. These might be caused by climate change, the spread of disease, pollution, invasive species, overfishing or other human-related impacts. 

An ecological system is said to be resilient if it keeps functioning even when the population of a species declines, or a species becomes extinct. A functioning ecosystem means the natural processes are working effectively, including those providing goods and services to humans, such as storing carbon, filtering water, or food to eat. 

Biodiverse and resilient marine ecosystems are made up of a large and abundant variety of different species. Each species in the ocean has a particular role to play. From tiny krill at the bottom of the ocean food web providing food to ocean mega-fauna like whales, to ocean apex predators such as bluefin tuna that prey on smaller fish and keep their populations in check. 

The more that biodiversity becomes depleted, the less nature can provide the food, economic and cultural benefits it currently provides to nature and humanity. But even if humans disappeared tomorrow, biodiversity would still remain vital to the planet’s success.

Does overfishing harm biodiversity?

Yes, fishing that is unsustainable or destructive can seriously impact biodiversity. Around 37.7% of the world’s fish stocks are currently overfished, and if this continues there will be less fish in the ocean for future generations as well as less biodiversity. 

Overfishing not only impacts the fish that are targeted for harvesting but also other marine life that interact with fishing vessels. Oceanic shark and ray species have declined by 71% since the 1970s, with overfishing the primary cause of decline. And bycatch – or unwanted catch – is one of the leading threats to marine biodiversity. It is estimated that 9.1 million tons (around 10% of annual catches) are discarded by marine commercial fisheries each year. 

How does the MSC Program help protect marine biodiversity?

The MSC program incentivizes sustainable fishing practices that ensure target stocks are healthy, fisheries are well managed, and the impacts on biodiversity are actively minimized. 

A key component of the MSC Fisheries Standard is assessing the fishery’s impact on the wider biodiversity and ecosystem. Many fisheries that enter the MSC program are given conditions of certification, which are a series of improvement goals they must meet to keep their certificate. 

From 2020 to 2023, these conditions led to a total of 437 improvements. This includes 80 improvements benefitting ecosystems and habitats and 166 improvements benefitting endangered, threatened and protected species and reducing bycatch among others. 

The Australian Eastern Tuna and Billfish Fishery introduced circle hooks, de-hookers, and line cutters to help mitigate turtle bycatch, and it implemented electronic monitoring on all its vessels. In Greenland, scientists at ZSL (Zoological Society of London) are helping map the seabed floor to help fisheries avoid vulnerable marine ecosystems. The work has identified over 230 groups of organisms from underwater images and has subsequently helped close all but two conditions relating to the wider ecosystem. In Cornwall, hake fishers have used pingers – acoustic devices – to prevent marine mammals from becoming entangled in gillnets, reducing harbor porpoise bycatch by 80%. 

The MSC Fisheries Standard is also reviewed and updated regularly, in line with global best practices, policies and science. An MSC analysis  shows that the average scores of fisheries significantly improve as they stay in the program. This shows that fisheries that remain in the MSC program actively improve their practices to reduce their impact on biodiversity. 

Supporting global biodiversity conventions with ocean data 

The MSC program also contributes to the work of United Nations’ (UN) bodies such as the Food and Agriculture Organization (FAO) in several ways. Data from the MSC is used by the UN Environment Program and other intergovernmental organizations to track progress towards international goals to end overfishing and protect biodiversity. In 2020, the MSC’s contribution to sustainable fishing and progress towards biodiversity goals was acknowledged by the UN in its Post-2020 Framework for Biological Diversity. 

How can seafood consumers help support marine biodiversity?

By using the MSC blue fish label on seafood products, brands, retailers, and restaurants are rewarding responsible fishing operations and incentivizing others to improve.

When you choose to eat sustainably certified, wild-caught seafood with the MSC blue fish label, you are helping to support a healthier, more resilient and productive ocean. There are thousands of MSC labelled products sold by retailers and restaurants around the world, making it easy to find sustainably sourced seafood.