0 OCEAN LITERACY Essential Principles & Fundamental Concepts of Ocean Science PRINCIPLE 5

1 REVISION HISTORY DateVersionRevised ByDescription Aug 25, VLOriginal

2 ESSENTIAL PRINCIPLE 5 5 The ocean supports a great diversity of life and ecosystems.

3 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(a) Ocean life ranges in size from the smallest virus to the largest animal that has lived on Earth, the blue whale. Extremes Ocean life is full of extremes with some of the smallest and largest creatures found there. Some of the smallest organisms found in the oceans include viruses, bacteria and other microbes. The largest creature that has ever lived on Earth is the blue whale. Adult females are the largest and measure 33m (108 ft) in length. Their tongue alone weighs the same as an elephant. The lion’s mane jellyfish can also be very long reaching 30m (100 ft) in length.

4 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(b) Most life in the ocean exists as microbes. Microbes are the most important primary producers in the ocean. Not only are they the most abundant life form in the ocean, they have extremely fast growth rates and life cycles. Primary Producers Most life in the ocean exists as micro-organisms or microbes including bacteria, blue-green bacteria and plankton. Microorganisms such as blue-green bacteria and phytoplankton (plant plankton) are the most important primary producers in the ocean. Not only are they the most abundant life form in the ocean, they also have extremely fast growth rates and life cycles.

5 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(c) Some major groups are found exclusively in the ocean. The diversity of major groups of organisms is much greater in the ocean than on land. Diversity We do not know how many species there are in the ocean or, indeed, on Earth. Estimates range from a few million to as many as 30 million of which we only know a small fraction! Biodiversity is a measure of the number of species in an ecosystem. For example, there are many different species of fishes but only a few species of sea otters. Fishes are, therefore, considered much more diverse than sea otters. The diversity of major groups of organisms is much greater in the ocean than on land with some major groups found exclusively in the ocean. One of the most diverse groups of animals in the ocean is the crustaceans. The crustaceans consist of some 39,000 known species distributed worldwide. Crabs, lobsters, and shrimps are among the best-known crustaceans but the group also includes an enormous variety of other forms.

6 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(d) Ocean biology provides many unique examples of life cycles, adaptations and important relationships among organisms (symbiosis, predator-prey dynamics and energy transfer) that do not occur on land. Ocean Biology Ocean biology provides many examples of life cycles, adaptations and important relationships between organisms including symbiosis and predator-prey dynamics. Adaptation An “adaptation” is a characteristic that generally increases an organism's ability to survive within a changing environment. For example, a fish’s mouth, teeth and jaws are adapted to the type of diet that specific fish eats. A fish’s body shape, color, and various appendages (e.g. barbels) are also adaptations. Relationships Food Pyramid – e.g. producers & consumers arranged in a hierarchy Predator-Prey – e.g. more effective predators-more evasive prey Symbiosis – e.g. clownfish/sea anemone, corals/zooxanthellae

7 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(e) The ocean is three-dimensional, offering vast living space and diverse habitats from the surface through the water column to the seafloor. Most of the living space on Earth is in the ocean. Living Space 3-D Vast Many diverse habitats from the surface to the seafloor Most of the living space on Earth is in the ocean. Life in the open ocean Life in the deep ocean However, this living space is “uneven”. Certain parts of the ocean are more hostile and difficult to live in than others.

8 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(f) Ocean habitats are defined by environmental factors. Due to interactions of abiotic factors such as salinity, temperature, oxygen, pH, light, nutrients, pressure, substrate and circulation, ocean life is not evenly distributed temporally or spatially, i.e., it is “patchy”. Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while much of the ocean is considered a desert. “Patchy” Ocean life is not evenly distributed temporally or spatially. Temporal For example, zooplankton migrate daily from the relative safety of the deep to the surface at night. During the day, the zooplankton move back. In addition, parts of the ocean experience seasonal blooms of plankton. This is a time of abundance for predators. However, this period is only temporary and, for the rest of the year, pickings are much leaner. In order to survive, predators must adapt by changing their diet or migrating to find other prey. Spatial Some regions of the ocean, such as coral reefs, support more diverse and abundant life than anywhere on Earth while much of the open ocean is considered a desert.

9 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(g) There are deep ocean ecosystems that are independent of energy from sunlight and photosynthetic organisms. Hydrothermal vents, submarine hot springs, methane cold seeps, and whale falls rely only on chemical energy and chemosynthetic organisms to support life. Deep Ocean Ecosystems Hydrothermal Vents Submarine Hot Springs Methane Cold Seeps Whale Falls Different To “Normal” Ecosystems Independent of energy from sunlight and photosynthetic organisms Use chemical energy and chemosynthetic organisms

10 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(h) Tides, waves and predation cause vertical zonation patterns along the shore, influencing the distribution and diversity of organisms. Living Along Coasts The coast is one of the most difficult habitats in which to live. Tides, waves and predators cause vertical zonation patterns along the shore, influencing the distribution and diversity of organisms. Some of the challenges organisms face include: 1. Winds 2. Waves 3. Currents 4. Temperature changes 5. Salinity changes 6. Drying out as the tide recedes 7. Predation Different life inhabits rocky coasts, sandy coasts and estuaries, with estuaries providing important and productive nursery areas for many marine and aquatic species. Each type of coast presents a different set of challenges to the animals and plants that lives there.

11 5 | THE OCEAN SUPPORTS A GREAT DIVERSITY OF LIFE AND ECOSYSTEMS 5(i) Estuaries provide important and productive nursery areas for many marine and aquatic species.