Chapter 9. Seas and coasts

Australia’s marine biodiversity is globally distinctive but its dimensions are still being discovered. This chapter looks at how science is being used to better explore and understand life in the oceans, and how it can inform better management decisions.

Australia's biodiversity: seas and coasts: Watch an interview with authors Dr Alan Butler and Dr Nic Bax (07:05)

Show transcript

[Music plays and text appears: Australia’s biodiversity – Seas and coasts]

[Image changes to show Dr. Alan Butler – Marine Ecologist]

Dr. Alan Butler: So the first thing you learn about marine biodiversity is that there are a lot of different kinds of plants and animals, more than there are on the land.

[Image changes to the ocean and rocks]

[Image changes to fish swimming in the ocean]

[Image changes to a diver next to a whale shark in the ocean]

Life originated in the oceans, and if you just consider animals for example there are about 33 different phyla, different large categories of animals, and 20 of them still only occur in the sea.

[Image changes to a star fish and text appears: Marine habitats]

[Image changes to a river and text appears: Estuaries and beaches]

[Image changes to a beach shoreline]

So habitats in the sea range from familiar ones like estuaries and beaches where you get animals that are different from the ones on land, but at least familiar to us, things like fish and worms, and cockles and so on.

[Image changes to a school of fish swimming in water]

[Image changes to the ocean and rocks]

[Image changes to a picture of fish swimming in the ocean]

Then moving into deeper water there are canyons for example cutting through the continental shelf and slope down into deep water.

[Image changes to computerised image of underwater canyons and text appears: Canyons and sea mounts]

Spectacular enormous canyons with filter feeding animals growing on the walls of the canyons.

[Image changes to various pictures of underwater animals and coral]

These are things like moss animals, Bryozoans, and corals, soft corals, and various kinds of worms with fan shaped crowns of tentacles.

[Image changes to Deep Ocean and text appears: Deep sea]

And then when you get even deeper it’s completely dark, you get animals that can’t see, and you get animals with various kinds of luminescent lures to catch their prey.

[Image changes to a deep sea creature]

[Image changes to deep sea ridges with bubbling water]

[Image changes to various deep sea animals]

In the really deep sea floor there are the mid-ocean ridges with belching hot water and sulphides support whole ecosystems of animals that don’t occur at all in shallow water, that don’t depend on plant photosynthesis for their energy, but depend on chemical synthesis instead.

[Image has changed back to Dr. Alan Butler]

[Image changes to computerised images of the ocean floor]

And when we’re mapping organisms in the sea we find that depth makes at least as much difference as latitude and longitude in determining what’ll be there.

[Image changes to a picture of an autonomous underwater vehicle and text appears: Deep sea exploration]

[Image changes to show Dr. Nic Bax – Marine Ecologist]

Dr. Nic Bax: It’s very difficult to sample the deep sea environment, it’s very costly, you need a large boat, you need to somehow get gear down to one kilometre below the surface, or two kilometres below the surface.

[Image changes to people working on a boat on the ocean]

Only recently in the last couple of years has Australia even managed to sample deeper than one kilometre below the surface. So recently when a U.S. ship came over to look at deep water corals off southern Tasmania for looking at climate change signals, we made sure that we were on that vessel and able to take some pictures of the biodiversity.

[Image changes to various pictures of underwater animals and coral]

So for the first time we were able to get pictures and estimates of the biodiversity, the biomass of animals, and down below about 1,200 metres. It was quite interesting because we found that quite dense area of biodiversity around 2,000 metres, which no-one knew about before. We found deep sea corals existing down at 3,500 metres, when we didn’t realise they could go to that depth. And so what this is doing, it’s as we gradually have the capacity to sample deeper and deeper we’re understanding how biodiverse that life is at depth. Once upon a time people thought the deep oceans were a desert, there was nothing there, and really that just indicated our lack of knowledge, our lack of capability of sampling that deep.

[Image has changed back to Dr. Nic Bax]

Now we can sample that deep we’re finding more and more animals, more and more ecosystems at those depths.

[Image changes to a picture of an autonomous underwater vehicle and text appears: New technologies aiding discovery]

[Image has changed back to Dr. Alan Butler]

The oceans are a difficult environment for human beings. We don’t take naturally to it (chuckles).

[Image changes to waves rushing in over rocks]

And so the discovery of our biodiversity has been mostly on the shore where you could walk at low tide, and then in shallow water.

[Image changes to a boat sailing on the ocean]

The challenges are to get down in deeper water to cope with the weather on the surface for a start; it’s difficult to work on ships and so on.

[Image changes to men working on a boat on the ocean]

But then we need equipment that can stand great depths, and that can be used remotely, because most of these depths are just too deep realistically for people to go by any means.

[Image changes to computerised footage of an autonomous underwater vehicle]

[Image changes to a man operating computerised machinery on a boat]

And things are really improving extremely fast in that regard. We now have autonomous vehicles that we can send down to enormous depths.

[Image changes to men on a boat releasing an autonomous underwater vehicle into the ocean and text appears: Autonomous vehicles]

And marine biology is really starting to piggyback on the inventions of the physical oceanographers.

[Image changes to an autonomous underwater vehicle]

[Image changes to a man viewing an Argo float on the floor]

So for example there are Argo floats which drift along at depth for ten days or so, and then come to the surface and radio their information back to the scientists, and then sink again, and drift on.

[Image changes to an Argo float floating on the surface of the ocean]

[Image changes to people working on an Argo float]

Those have not only revolutionalised(?) physical oceanography, what we know about the currents and the tides and so on, but we’re starting to attach biological sensors to them so that we’re getting information about biology as well.

[Image changes to an Argo float being lowered down the side of a boat into the ocean]

[Image changes a person recording data]

[Image changes to people in a boat on the ocean]

Another thing we’re able to do really well now, that was primitive only a decade or more ago, is to attach tags to animals.

[Image changes to a turtle swimming in the water and text appears: Tagging animals]

[Image changes to a turtle being tagged]

[Image changes to an image of a transmitter attached to a turtle’s back

We use to tag fish routinely by simply sticking a number on them, but now we can attach transmitters which measure depth and temperature and things like that, and these kinds of tags are being put on fish and marine mammals, and yielding enormous amounts of information about the biology of the animals.

[Image changes to a shark with a tag]

[Image changes to a seal with a transmitter attached to its head]

[Image has changed back to Dr. Alan Butler]

But incidentally also enormous amounts of information about the sea, because the animals are effectively carrying sensors around for us.

[Image changes to people on a boat in the ocean]

[Image changes to penguins on an iceberg]

So we’re learning about ocean currents and tides, and we’re learning about conditions in places where we can’t go, such as under the sea ice in Antarctica.

[Image changes to computerised spreadsheet and text appears: Genomic technology]

And finally there’s genomic technology, so we can now sequence genomes.

[Image changes to an autonomous underwater vehicle]

We can use robotic sensors to get samples from all sorts of places and depths, and we can analyse them for information about what organisms are there, and how they’re living, what sorts of enzymes they’re using, whether they’re fixing nitrogen, a whole lot of things about how the ecosystem works.

[Image changes to fish swimming in the ocean]

These new technologies are really wonderful. I think they represent a revolution in marine ecology in the coming few years.

[Image changes to diver with an autonomous underwater vehicle and text appears: Future challenges]

[Image has changed back to Dr. Alan Butler]

The biggest challenge still is discovery.

[Text appears: Discovery]

We’re still discovering what’s there, and so that will continue to be a challenge for a while.

[Image changes to a boat on the ocean]

[Image changes to men working on a boat on the ocean and text appears: Ecosystem function]

We need to keep learning how it works, how the ecosystem functions, and we now have technologies that will help us do that.

[Image changes to a car towing a boat]

But along with it, we can’t wait til we know everything, along with it we have to manage our impact on the seas, and that’s going to get greater and greater because human population is increasing, and human activities are increasing.

[Image changes to a large boat on the ocean and text appears: Managing human impacts]

[Image changes to a pontoon on the ocean]

[Image changes to boats on the ocean]

[Image changes to people fishing off rocks]

[Image changes to people surfing]

So I think that there is also a societal challenge in debating what we want out of our seas, what we want them to be like, what matters and what doesn’t, which changes are tolerable, and which have to be resisted by some means or other.

[Image changes to a diver holding seaweed under the ocean]

[Image changes to a diver recording data under the ocean]

[Image changes to a diver under the ocean]

[Image has changed back to Dr. Alan Butler]

So I think the role of scientists is to provide the best information to allow that discussion to continue.

[Text appears: MUSIC – Nicolas Del Pozo; ADDITONAL FOOTAGE – UC San Diego Argo Project; ADDITIONAL IMAGES – NASA, GeoScience Carl Davies, Marie Davies, Wayne Osborne, Elvira Poloczanska, Justin Gilligan, Chris Oosthuizen, Kim Brooks Creative commons images (Flickr, Wikimedia): Alexander Vasenin, Neptune Canada, NOAA Pacific Ring of Fire 2004 Expedition]

[Music plays and CSIRO logo appears with text: Big ideas start here www.csiro.au]

Hide transcript

There are two big challenges in managing biodiversity of our seas and coasts: understanding Australia’s marine biodiversity and agreeing on goals for its management.

Chapter overview

Australia’s marine biodiversity is globally distinctive. The biggest obstacle to understanding it, and providing clear advice on managing it, is still the difficulty of describing and measuring it. Australian scientists are working to:

  • develop smarter ways of detecting and measuring biodiversity
  • improve our use of surrogates – things that provide insights into a plant or animal of interest but are easier to measure than that species
  • understand marine connectivity – a feature that means, for example, that biodiversity depleted in one area may possibly be recolonised with biodiversity from another.

Collaboration between scientists, managers and society is vital for managing our marine biodiversity while supporting sustainable development of our marine industries. Already, Australia has developed a science-based participatory process for fisheries management within a clear legislative framework.

Australia is also participating in international marine management for southern bluefin tuna, Antarctic marine living resources, and identification of ecologically significant areas on the high seas.

Download the chapter or the whole book [PDF and EPUB versions available]

Chapter authors

Alan Butler and Nicholas Bax

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