All About Seafood

About sea creatures

Studies have demonstrated that fish aren’t just capable of feeling pain, but are willing to pay a cost to avoid pain. Zebrafish were given access to two tanks; one completely barren, and one with enrichment. Unsurprisingly, all zebrafish chose the enriched tank. The fish were then injected with a painful acid, and the barren tank contained pain-numbing anaesthetic. The fish assessed their choices, and all chose to stay in the barren tank to relieve themselves of the pain [1]. 

Research on fish has shown that their cognitive abilities often match or exceed other vertebrates and that their behaviours exhibit consciousness, self-awareness, and therefore, sentience [2]!

Fish were found to communicate with each other using squeaks and other low-frequency sounds that are outside of the human hearing range [3], as well as “sign language” or “Morse code”. For example, lionfish wave the row of fins on their backs in a certain way to signal for other fish to join them in a hunt [4]. Large groupers are known to alert moray eels to hunt fish concealed in a crevice by shimmying their bodies and pointing their noses towards where the fish is hiding [5].

The industry

The seafood industry measures the number of lives killed in tonnes, rather than an actual number of individuals. It is estimated, however, that humans kill between 1-3 trillion sea animals every year [6]. To meet our collective demands, the industry uses trawlers, longlines, and aquafarms. These methods are causing irreversible damage to the ocean and the world as we know it.  

Trawling is one of the most common methods of fishing. It involves towing huge nets – sometimes the size of a football field – behind a boat either through the middle of the ocean or along the seafloor [7]. This method captures every single animal unlucky enough to swim in its path. These boats haul up tens of thousands of fish in a single load. Trawling is basically the underwater equivalent of clear-cutting forests. Our demand for seafood is emptying the oceans at an alarming pace and depleting precious sea life.

To cater to our ever-increasing demand for seafood, the number of fish and crustacean farms is increasing. We are now breeding, raising, and mass-producing sea creatures in artificial environments so they can be sold as food. Approximately 44% of total global fish production comes from aquaculture [8]. These factory farming systems are built to maximise production and minimise costs.

The cramped enclosures they live in inhibit their ability to move and cause them to knock against each other. As a result, many fish suffer from parasitic infections, blindness, deafness, diseases, severe injuries, and even depression [9, 10]. In 2016, researchers examined the brains of sluggish, stunted salmon on farms, and found sky-high measures of the stress hormone cortisol. Their serotonin levels mirrored those of depressed mammals [11]. 

Most species of farmed fish and crustaceans are carnivorous, which means that additional fish must be caught from our already-exhausted oceans to feed them. This makes aquaculture (seafood farming) unsustainable. It is estimated that 37% of all global seafood is now ground into fish feed [12]. Every kilogram of salmon or prawns can use up 2.5-5.0 kg of wild fish as feed [13] and a seafood wholesaler estimated that it takes 57.3 kilograms (26 pounds) of fish from the ocean to produce just 1 kilogram (1 pound) of farmed bluefin tuna [14]! 

At last count in 2014, 80% of commercial fish stocks were declared fully exploited or overexploited [15]. Almost 31% of the world’s fish populations are overfished, and another 58% are fished at the maximum sustainable level [16]. It is predicted that if fishing rates continue, all the world’s fisheries will collapse by the year 2048 [17]. 

Trawlers and longlines both result in by-catch, where non-target species, such as dolphins, whales, sea turtles, rays, seabirds, crabs, and sharks, are caught, trapped, hooked, or become entangled [18]. According to global estimates, around 38 million tonnes of unwanted sea life are caught, making up 40% of the world’s catch [19, 20]! For every kilogram of fish caught, there is up to 2.3 kilograms of non-target species, and for every 1 kilogram of prawns, there is around 5 to 20 kilograms of bycatch in the nets [21]. OCEANA estimated that 150 turtles are captured per day, and more than 100 million sharks every year [22]. 

Trawling is also largely responsible for diminishing the most valuable sea creature, phytoplankton. Phytoplankton are responsible for producing 80% of the world’s oxygen – this means, most of the oxygen we breath is from the ocean! According to Watson, the founder of the Shepherd Conservation Society, “Since 1950, there’s been a diminishment by 40% of all the phytoplankton in all the world’s oceans… If we lose phytoplankton, we don’t survive” [23].

The environment

Commercial fishing is responsible for most of the great ocean garbage patch, with lost or purposefully discarded fishing nets accounting for 46% of the trash, and the rest being ropes, oyster spacers, eel traps, crates, lines, and baskets [24]. Discarded fishing equipment is responsible for around 30% of the decline in some fish populations, and more than 70% of marine animal entanglements involve abandoned plastic fishing nets [25].

Our health

Microplastics are being consumed by fish and accumulate up the food chain, ending up on our plates. Studies detected plastic in all fish muscle samples [26]. On top of ingesting plastic, the plastic particles can also release absorbed pollutants like PCBs and chemical additives like BPA. These pollutants and additives can increase the risks of cancers, cause hormone disruption, and DNA damage. A study of more than 12,000 food and feed samples across 18 countries found that the highest PCB contamination was found in fish and fish oil, followed by eggs, dairy, and then other meats. The lowest contamination was found at the bottom of the food chain, in plants [77].