Seafloor Ecology Habitats and Food Chains Insert image

Seafloor Ecology Habitats and Food Chains Insert image of animals under the sea

The marine environment • Around 71% of the Earth’s surface is covered by oceans • Oceans form one of the largest habitats on earth and many parts have only recently begun to be explored • Studying the seafloor is important to our understanding of how animals live and survive in the marine environment.

Habitats A habitat is an area where a group of animals live. There are many different habitats around earth. Some animals don’t always stay in the same habitat, but move depending on factors such as the season. Image different habitats, desert, cold mountains, rivers & trees, marine

Marine Habitats Like anywhere else the marine environment contains many different types of habitat. Due to the size and depth of some marine habitats little is known about them and very few have been explored.

Open Ocean The open ocean is anywhere in the ocean not near the coast or seafloor. While this is a large part of Earth’s surface it is low in nutrients and animals in this habitat often travel long distances. Animals which live in the open ocean around the UK include: seagulls, sharks, squid, seals, basking sharks and salmon.

Rocky seafloor The rocky seafloor is part of the seabed. Animals here live permanently directly above, on or under the seabed. Many of the animals have adapted to the habitat by clinging onto the rocks or using the material as homes. Animals that live in the rocky seafloor around the UK include: ross worms, amphipods, starfish, octopus and gobies.

Sandy Seafloor The sandy seafloor is the part of the seabed which is mostly made up of sand sediments. Though it doesn’t look like much would live here there a wide number of animals that call the sandy seafloor home. Animals which live in the sandy seafloor around the UK include: catworms, shrimps and polychaetes.

Food • As well as a home all living things need food for energy • For many animals this energy comes from other animals • We can classify animals by how they get their energy Herbivores eat only plant material Omnivores eat both plants and animals for energy Carnivores eat only meat or the flesh of other animals

Below are three marine animals, can you guess which is an omnivore, which is a herbivore and which is a carnivore?

Seals are carnivores – they feed mostly on squid, octopus and fish. Zooplankton are herbivores – they feed on phytoplankton. Sea urchins are omnivores – feeding on barnacles, algae and seaweed.

Trophic Pyramid Feeding relationships can be classified on an trophic (or ecological) pyramid. Trophic means feeding, therefore each level on the pyramid shows a different system of feeding. Animals fit into the pyramid according to how they get their energy. .

Producers make their own food. In the oceans they convert energy from the sun into food through photosynthesis. Examples of producers include seaweeds and phytoplankton.

Consumers do not make their own food, instead they consume other living things. Consumers can be herbivores, omnivores or carnivores. There are three levels of consumers; 1 st, 2 nd & 3 rd.

Decomposers do not fit into one level of the pyramid as they are everywhere. These are the bacteria that feed the life cycle by breaking down waste or dead organisms.

Food chains • Food chains are simple diagrams showing what animals eat. • The animal next up the chain eats the one below and so on. • This shows the flow of energy from the bottom to the top. • Food chains are more specific versions of ecological pyramids.

Food webs • Food webs are far more complicated than food chains. • Food webs show the relationships between producers, consumers and decomposers in a habitat. • A food web that links all animals and plants in an environment would be very confusing and hard to understand.

Food webs • To simplify food webs specific animals are used to represent a whole group. • By studying food webs scientists can learn about relationships between animals in the marine environment. • Food webs help scientists understand how fishing, pollution and other marine industries affect the oceans and the animals living there.

Environmental Impact • Food webs help us understand the complex relationships in the marine environment. • When something happens in the environment it can impact on other things. • Using the previous food web imagine what would happen if there was an oil spill which covered all the mammals and birds. • What if all there was a massive increase in phytoplankton – such as when there is an algal bloom? • The relationships in a food web mean that when something happens to one organism it will have an effect on many of the other organisms it is linked to in a food chain.

RECs • Scientists are continually studying the seafloor to find out more information about it. • Recently UK scientists have been involved in the Regional Environmental Characterisation surveys or RECs for short. • These studies looked at the archaeology, geology and ecology of the seafloor around the UK. • Here we are going to focus on the results of the ecological studies. • But first, what is ecology?

Marine Ecology • A huge number of scientists were involved in creating the four RECs. One important group were the marine ecologists. • Marine = related to the sea or saltwater environment • Ecology = the study of living things and how they interact with each other and their environment • Marine ecologists study living things in the ocean, or marine environment, and how they behave and interact with their environment.

Habitat • • Ecologists can investigate habitats using many methods. Two methods of exploring the seafloor are explained here. When dealing with a very small area of seabed which is not very deep divers can be sent down. Once on the seafloor divers are able to take pictures and pick up samples. Another method is to use cameras and Remote Operate Vehicles to take photographs and video of the animals and their habitats.

Animals • To collect animals the scientists use Beam trawls and Hamon grabs. • Beam trawls involve towing large nets across the seafloor. The net is held open by a large metal beam. • These nets pick up creatures which live on and near the seafloor. • Hamon grabs work by lowering large claws onto the seafloor from a boat. The claws then close collecting organisms and seafloor. • Hamon grabs are useful for studying habitats also as they pick up seafloor samples.

Food Chain • During the RECs, scientists focused on measuring and recording animals which lived on and in the seafloor. • They know that any changes to these organisms will ripple up the food chain causing problems for many other animals.

Human Impact • Now that you have seen how animals in the food web interact you can imagine what would happen when humans impact on the environment. • The REC studies provide a benchmark of how healthy the seabed is, future studies can measure any changes. • It is important that we keep investigating the seafloor to help us use it sustainably in the future.

Discussion Questions • • Why are food chains and webs important to understand? What is the most important level in an trophic pyramid? What would happen to top consumers if there was no sun? Why do we need to use the sea sustainably? How do we know if we are using the sea sustainably? What type of consumer are you? What affect do you think climate change will have on the oceans?