Habitat loss is a major cause of extinction globally, and although we see this issue most clearly on land, the ocean's inhabitants are not immune. The seas may seem vast, but many species are native only to very small portions of it, rely on specific environments for nursing their young, or depend on local feeding grounds.
Destruction and degradation of these environments put life at risk - here are 10 species at the Two Oceans Aquarium whose wild populations are at risk due to the loss of their habitats.
African penguins are a poster child of a species potentially facing extinction due to habitat loss. Hundreds of years of egg-poaching, guano mining and overfishing of their main food sources have forced African penguins to leave many of their colonies and try to establish newer footholds - such as the famous Boulders Beach colony. However, this is far from an ideal habitat for them and they now face new risks.
Knysna seahorses hold the title of "world's most endangered seahorse" - one that no South African should be proud of. They are found only in the Swartvlei and Knysna estuaries, where pollution and changes to the shape of the estuaries caused by construction have resulted in mass mortality.
Green sea turtles
A near-global species, green sea turtles are at risk due to habitat destruction at all points in their lives. Their nesting beaches have been largely devastated by litter, feral dogs and rats, light pollution, construction, erosion and careless human use. The fertile feeding grounds that juveniles depend on are largely overexploited by commercial fisheries, and even the large adults are regularly caught as bycatch by longline fisheries or trapped in abandoned fishing gear allowed to drift in the ocean.
Have you ever wondered what goes on behind the scenes of the Two Oceans Aquarium's turtle rehab centre? Want to know what you can do to support sea turtle conservation? Find out here.
Seventy-four sea breams are large, deep ocean dwellers that return to the same location annually to breed. Unfortunately, these predictable locations have been overexploited by fisheries, even for decades after the collapse of the fish stock in the 1960s. Although many of these important spawning locations are now protected, illegal fishing, as well as the low number of remaining adult seventy-fours in these areas, has severely hampered their recovery.
The seventy-four is now Critically Endangered, the most severe rating on the IUCN Red List.
The seventy-four is not the only WWF SASSI Red-listed fish at the Aquarium. Here are 16 species that you should keep off your menu.
St. Joseph sharks
St. Joseph sharks are one of the few species of chimaera that inhabit shallow, coastal waters where they spend much of their young lives in the shallow nurseries where they hatch. Unfortunately, this makes them susceptible to being caught in large numbers as bycatch by various fishing activities in these waters.
Dageraads inhabit rocky reefs on the coast of the southeastern Cape - making them prime targets for shore fishing. All dageraads begin life as females, only changing to male when they grow over 40cm. Unfortunately, their slow growth rates and the fact that they prefer to stay near one reef means that each individual dageraad has a very low chance of growing to a sufficient size to become male before being caught.
Quick tip: Look out for the Marine Stewardship Council's "blue label" when you're at the shops and looking to buy seafood. If you see this on the packaging, you can be assured that the fish you're buying has been sustainably sourced.
The issues facing perlemoen, or abalone, are no secret - large-scale poaching, badly managed fisheries, an obsession with free ashtrays, etc. What few people know is that this decline is linked to habitat degradation caused by another endangered animal, the West Coast rock lobster. Young abalone are easy meals for fish, so they hide under the spines of sea urchins. A recent influx of kreef to the Southern Cape coast has caused a decline in the local sea urchin population and with it a decline in juvenile abalone.
White steenbras were once an abundant fish in South African numbers, but the destruction of their spawning habitats have resulted in a decline to just 5% of their original population. White streenbras spawn in estuaries where fishermen have targeted them en masse and where pollution has affected them heavily.
Giant kob, sometimes called dusky kob or kabeljou, are subject to severe overfishing, and face the destruction of their estuarine spawning grounds. Numbers have been depleted to as little as 1% of their original stock, and for that reason, they are on the WWF SASSI red list.
"Giant" kob are not the only massive species at the Two Oceans Aquarium. Here are 5 other's that are worthy of the name "giant".
African black oystercatchers
With fewer than 10 000 African oystercatchers left in the wild, their habitat needs to be protected from human abuses. Holiday-goers often disturb oystercatchers and drive them away from their nests, causing their eggs to overheat in the sun. Scavengers, like kelp gulls and dogs, are attracted to human trash and inevitably feed on oystercatcher eggs they find. Simple human lifestyle choices are driving one of our most iconic coastal birds towards extinction.
These 10 species are just a few South African treasures who's habitats need protection - let's work together to ensure that our coasts are protected.
You can be part of protecting our environmental heritage for future generations by supporting the implementation of Marine Protected Areas by or government. You can learn more about MPAs at our recently installed MzanSea Marine Protected Areas exhibit at the Two Oceans Aquarium.