As a child you may have been fascinated by Jules Verne’s Twenty Thousand Leagues Under the Sea or Herman Melville’s Moby Dick. Perhaps you also read about how Jacques Cousteau, a naval officer and explorer, invented “Aqua-Lungs” (underwater breathing equipment) and pioneered marine conservation. What did all famous people have in common? A fascination for marine life.
This fascination led to development of Marine Biology, the study of marine organisms in the sea found in diverse habitats and depths in the oceans. The organism’s size and whether it is observable by the naked eye is no limitation as microscopic plankton or whale sharks are of equal interest! Understanding marine life is important as humans rely on its usage for food, raw materials, leisure (diving, snorkelling), tourism and jobs.
As seen with life on Earth, the underwater world relies on defined habitats including:
- Coastal habitats are areas along and close to marine shorelines. They are important in limiting the impacts of climate change for example as acting as barriers against floods. Mangrove tangled roots provide protection for smaller fish against hungry predators and shark nurseries. Some shrimp, crabs and fish reside in salt marshes which absorb rainwater and sinks excessive carbon.
- Estuaries are partially enclosed water bodies with one or more streams or rivers flowing into it as well as a connection to the open sea. As such they act as “transition zones” between freshwater and saltwater environments. This property means it contains abundant nutrient levels and harbours highly diverse life. For example, the Chesapeake Bay in the Unites States, contains oyster reefs (oyster, mud crabs, small fish) with seahorses, fish and migratory birds.
- Coral reefs are characterised by their vibrant colours and sheltering of some of the most diverse wildlife. Australia’s Great Barrier Reef for example contains over “1500 fish species, 411 types of hard corals, 1/3 of the world’s soft corals, 134 shark and ray species, 6/7 endangered turtle species and 30 marine mammal species” states the WWF (World Wildlife organisation). However, global warming contributes to ocean temperatures and the bleaching or colour-loss of corals which threaten the marine biodiversity.
The CPD accredited courses are carefully crafted to help you gain in-depth knowledge on a topic of your interest.
Marine wildlife can mostly be classified in 5 subdomains:
- Microscopic life: important for the cycling of carbon, nitrogen and nutrients as well as photosynthesis (conversion of life energy into chemical energy). Examples include cyanobacteria or marine viruses.
- Fungi: survive by living on or inside other living organisms such as corals and algae.
- Plants and algae: both microscopic and macroscopic algae are important for marine wildlife, used as nutrients, hiding spots or nursery shelters. Examples include kelp or turtle grass.
- Invertebrates: have no backbone and include jellyfish, sea worms, shellfish, starfish.
- Vertebrates: include fish (bony and cartilaginous fish), reptiles (turtles, snakes, crocodiles), birds (gulls, penguins) and mammals (whales, dolphins, polar bears).