Habitats, food webs and adaptations
Riley and Steve Hathaway want to change the way young people think and act towards the ocean. Their vision is to “Inspire kids to enjoy and care for the world’s oceans”.
Marine trophic pyramid
Food webs throughout the world all have the same basic trophic levels. However, the number and type of species that make up each level varies greatly between different areas and different ecosystems.
Science ideas and concepts in Young Ocean Explorers
In between the smiles, light-hearted banter and stunning underwater shots, Riley introduces a number of important science concepts:
A habitat is the natural home or environment of a living thing.
In a food web, energy and nutrients are passed from one living thing to another.
Adaptation is an evolutionary process in which an organism becomes well suited to living in a particular habitat.
Resources on the Science Learning Hub provide an in-depth means to further explore these concepts.
Marine habitats
Riley explores several marine habitats. In Harbours (episode 2), she discovers a busy underwater city that acts as a crèche for young fish, providing them with food and protection.
While exploring the kelp forests in episode 8, Riley finds snails, shrimps, crabs and sponges living among the seaweed.
New Zealand’s marine environment is incredibly diverse and is made up of a large number of habitats. Different habitats have different characteristics due to wave action, light, temperature substrate (sandy or muddy) and other factors. For example, Sandager’s wrasse fish (episode 6) need a habitat with a sandy floor, as this is where they sleep. Sea turtles (episode 9) visit New Zealand but don’t live here because the water is too cold.
Learn more about aquatic habitats
A habitat is the specific natural area in which an organism or group of organisms live and breed. These Hub resources provide more information about aquatic habitats. Marine habitats Habitats in the Bay of Plenty Life on a reef
New Zealand’s marine environment
In this video, Dr Candida Savage, from the University of Otago, talks about how New Zealand’s pristine habitats are like ‘natural laboratories’. This is because they offer good opportunities to study naturally functioning systems and to learn more about what different habitats may have been like before human impact.
Activity ideas
Students learn about the characteristics of three marine habitats (harbour, surf beach and rocky shore) and match plants and animals with each habitat, according to their adaptive features. Where do I live?
Students discuss how a variety of everyday objects serve as metaphors for the characteristics and functions of estuaries. Estuary metaphors
Marine food web
As Riley learns about rays (episode 1), crayfish (episode 3), orcas (episode 4) and sharks (episode 10), she mentions the food these creatures like to eat – and what eats them as well. In any food web, energy and nutrients are passed from one living thing to another. Food webs vary according to habitat, but all food webs have some things in common.
Primary producers make up the base of a food web. Phytoplankton, seaweeds like kelp (episode 8) and seagrasses make their own food by converting energy from the Sun through photosynthesis. Consumers cannot make their own food so they need to get food from other sources. For example, Riley tells us that rays eat shellfish, crabs and fish, but in turn, rays are eaten by sharks and orcas. Another important but often overlooked part of the food web is the decomposers. Bacteria and other organisms break down dead plants and animals, releasing the nutrients back into the ecosystem.
Learn more about marine food webs
Food webs show the networks of feeding relationships between organisms that live in a particular habitat. These Hub resources provide more information about marine food webs. Marine food webs The bottom of the food chain Understanding food webs in Fiordland Tuna sandwich
Understanding food webs
In this video, Associate Professor Stephen Wing, from the University of Otago, talks about how our understanding of food webs has changed over the years. We now have a much better understanding about the complex networks of interactions between organisms and the place of humans in the food web.
Point of interest Think about where the fish in your meal of fish and chips comes from. Where does it fit in the marine food web, and what other species is it linked to?
Activity ideas
Students build their own food web using images of organisms from the marine ecosystem. The activity can be completed indoors or outside. Build a marine food web
This activity is a practical way for students to understand the complexity of food webs. Making a food web
This interactive diagram explores food webs and other aspects of life in the sea. Marine ecosystem
Adaptations of marine creatures
Riley explains some of the unusual characteristics of creatures found in New Zealand’s seas. These characteristics enable the creatures to live in a particular environment and are often referred to as adaptations. Adaptations are generally grouped into three main categories: structural, physiological and behavioural.
Structural adaptations adaptations are the physical features of the organisms. For example, crayfish (episode 3) have spiky exoskeletons for protection because everyone wants to eat them! Kelp (episode 8) has honeycomb cells filled with air to help it bounce back from ocean waves. Kelp’s slimy coating protects it when the tide is out. Rays (episode 1), dolphins (episode 7) and sharks (episode 10) all have specialised teeth and eyesight to help them hunt or survive being hunted.
Physiological adaptations adaptations enable an organism to regulate how its body functions. For example, Sandager’s wrasse fish (episode 6) are all born female, but if a group’s male dies, the ‘bossiest’ female in the group becomes a male fish within 2 weeks.
Behavioural adaptations adaptations are learned or inherited behaviours that help an organism survive. For example, adult orcas (episode 4) teach their young how to hunt in groups and communicate with others in their pod to surround their prey.
Sea star adaptations – dorsal view
Sea stars have many weird and wonderful adaptations including both sexual and asexual reproduction. Click on any of the labels in this interactive to view short video clips or images to learn more.
Sea star adaptations – ventral view
Sea stars have many weird and wonderful adaptations - including some unusual internal systems. Click on any of the labels in this interactive to view short video clips or images to learn more.
Learn more about marine adaptations
Adaptation is an evolutionary process in which an organism becomes well suited to living in a particular habitat. These Hub resources provide more information about marine adaptations. Adaptations of marine organisms Adapting to marine habitats
Activity ideas
Explore some of the adaptations fish use for camouflage. Hiding in plain sight
Use reading skills to locate and integrate information about animal and plant adaptions, and use these to design a unique animal or plant. Animal and plant adaptations
Nature of science
Scientific understanding is based on observations of the world around us from which interpretations are made. Riley’s first-hand observations and interviews with experts provide examples that help illustrate and explain fundamental marine science concepts.
Useful links
Visit Te Ara website to learn more about these topics:
Go here to purchase a copy of the Young Ocean Explorers DVD and Love Our Ocean book.
