POLLUTION OF OUR SEAS - PART III - OCEANIC BUILDING BLOCKS OF LIFE

POLLUTION OF OUR SEAS - PART III - OCEANIC BUILDING BLOCKS OF LIFE

Part II examined the role of the Sea and the Sun

As sailors and lovers of the sea, we can all contribute to preserving our playground by reducing marine pollution.

The prolongation of marine biodiversity depends on the marine food chain and commences with microscopic phytoplankton and zooplankton. The chain builds up to the largest creature on Planet Earth; The Blue Whale.

At its biggest, this baleen whale (filter feeder) reaches almost 30 meters long and weighs in at more than 170 MT. It reaches these gigantic proportions on a diet of euphausiids (krill); as much as 3,500 Kg per day.

Krill are a type of shrimp ranging in size from under 1 cm up to 14 cm in length that congregate in large “swarms”. Antarctic krill (around 6 cm in length) have a life span of about 5 to 10 years. Females produce almost 1,000 eggs each summer which are laid at the surface but fall to great depths. Krill spend their days in the darker depths of the ocean and swim to the surface each night to feed on phytoplankton (single-cell plants) but some tropical krill also eat zooplankton (single-cell animals). Zooplankton diet includes phytoplankton.

There is a multitude of other creatures below the cetaceans (whales and dolphins) whose survival depends on phytoplankton.

Phytoplankton and zooplankton mortality increases with rising seas temperatures and increasing concentrations of surfactants, acids and alkalis. Increases in mortality adversely affect the whole marine food chain and the biodiversity of our seas and oceans.

Reductions on phytoplankton levels also have a serious adverse effect on the land and Earth’s atmosphere. Plant and animal life on land and in the air depend upon the survival of phytoplankton. If we do not protect the basic building blocks of life a vicious circle will develop and we will destroy our planet - human life included.

Part IV will show the major role phytoplankton play in keeping our planet alive.