Giants of the Deep

Source: Food and Agriculture Organization of the United Nations, 2013, Caroline Hattam, Plymouth Marine Laboratory,   "The Youth Guide to Biodiversity" 1st Edition (Chapter 8) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 8. Verbatim.

The marine environment is home to a number of giant animals, for example:

:: The blue whale is known to grow to over 30 m and can weigh as much as 181 tonnes (the same as almost 20 cars)! 

:: Giant clams can grow to over a metre in size and may live for over 100 years.

:: The colossal squid is even bigger than the giant squid. Colossal squids weigh about the same as a small cow (about 500 kg) and can measure over 10 m. 

:: Giant isopods, distant relatives of garden woodlice (also known as pill bugs), can grow to over 30 cm in length. 

Many of these giant creatures grow very slowly and take many years to mature and produce offspring. This makes them very susceptible to human activities and environmental change as they are slow to adapt. 

Marine Habitats

Great barrier reef, Australia.

© Rosaria Macri

Coastal areas are very productive and support large numbers of marine organisms. The number of marine organisms is often greatest in relatively shallow coastal areas because they are rich in nutrients and light. Many of these nutrients, which are food for marine life, come from the land. Some coastal areas are extremely diverse, for example coral reefs (see box: “Coral Reefs”).

Coral Reefs

Coral reefs are one of the most diverse ecosystems on the planet, containing very high numbers of marine species. Scientists have so far described 4 000 reef fish and 800 coral species. Coral reefs are also important for people and they provide income, food and a livelihood for more than 500 million people, mostly in developing countries. Corals are very sensitive to changes in sea temperature and there are fears that global warming will cause the death of many coral reefs.