Earth (2017)

Many scientists are working on ways to manage local threats to coral reefs. This includes sustainable fishing, establishing marine protected areas, maintaining vegetation near rivers to trap sediment, banning dynamite and cyanide fishing, etc. We are also developing ways to reduce future CO2 emissions through using renewable energy, increasing energy efficiency, and alternative transport. And we are looking at ways to capture and store CO2 to avoid atmospheric levels increasing so fast (and eventually hopefully decreasing again).

Some teams are developing ways to actively manage reefs in the future, included selective breeding of thermally-tolerant corals and their zooxanthellae (the plant-like cells they host in their tissue that give them energy from photosynthesis), planning assisted migrations of corals to areas that they will be suited to in the future, and breeding corals in the lab to release into areas when bleaching or other devastating impacts occur.

I even have a student looking at the changing soundscapes of degraded reefs to assess whether we can manipulate local acoustics to help reefs to recover (watch this space).

No one is average. We can all make positive changes to improve the heath of the oceans. These include eating sustainably caught fish, pressuring and supporting politicians to make strong and positive policy to protect the environment, choosing renewable energy tariffs, participating in beach cleans, avoiding plastic and recycling wherever possible,

We put lots of ideas together for this page on the Blue Planet 2 website:

http://www.bbc.co.uk/programmes/articles/1FlfcGGKPSWv3m7JdfBT5dv/get-involved-with-ocean-conservation

Donations and offering time to help on projects can definitely help. Contact your national marine charities (e.g. Marine Conservation Society in the UK), your local or your alumnus university, or search crowdfunding pages for ideas, but be careful not to be exploited by scientifically dubious initiatives (if in doubt, ask an expert first).

I am lucky to have cuttlefish that come into the bays just south of Exeter in the summer so have spent many happy evenings doing and snorkelling with them. They are remarkable, intelligent, inquisitive, memorising creatures that, once you have built trust, love to play. So I wouldn't say they freak me out, rather that they intrigue me and quickly demand a certain degree of respect.

I know the feeling! That is the skill of the film crews and underwater photographers. They use camouflage, very thick wetsuits and rebreathers that allow them to stay underwater for hours at a time, and rely on a good sense of humour to get them through days when nothing seems to be happening. They also have equipment that allows them to monitor animals and habitats 24/7, including drones, 360-degree cameras, night vision lighting and sensors, and some very, very patient and dedicated researchers, spotters and local assistants.

Even so, they might spend a month shooting what ends up as less than a minute of footage. This meagre return for effort means that as scientists we tend to work on more commonly-observed animal interactions, often using model species that are easier to monitor and that are abundant so we can replicate our study across many individuals. These systems are more reliable but rarely quite as spectacular as this on Blue Planet 2.

We have only been using plastic for the past century, and impacts of plastic in the marine environment have only recently been observed and considered, so we are at a turning point. There are some stories of success, for example by introducing the 5p plastic bag tax in the UK, the number of bags washed up on beached has reduced by 40% (http://www.bbc.com/news/uk-38053404).

I know that, partly as a result of watching Blue Planet 2, the public are talking about managing plastic waste in a new way. The UK Government have promised a consultation on single-use plastics, people are turning away drinking straws, plastic bags and disposable coffee cups, and there is growing pressure on supermarkets to reduce plastic packaging.

I really hope that progress will accelerate in your part of the world so that in 10 years time, we will look back on 2017 as the year we hit "peak plastic" and that we have found innovative and rediscovered traditional solutions for packaging and mass production.

Congratulations on your degree! Marine ecology is a fantastic direction for your career, and there are many ways you can go. These include research in a University or Science Institute, teaching in a University, developing and applying Policy, working for Conservation Agencies or pressure groups, working in offshore industries, consultancy, ecotourism, etc.

If you are planning on grad school that will give you valuable experience of different sectors to work out what you want to do and deepen your experience. In your year out, you should try to gain experience. For example, learn to dive (industry minimum is PADI Rescue or BSAC Dive Leader with 20+ hours experience), learn to drive boats, help on a project (volunteering generally gets you to the better jobs, paid work will involve more monotonous lab work (equally important, but can be less fun!).

I had a year out before my PhD where I worked at a marine station in Scotland, worked at a consultancy in Liverpool, volunteered with the Australian Institute of Marine Science and helped to run a expedition in Belize. These experiences were invaluable.

Wow, there are so many! The sleeping sperm whales, the sea lions hunting tuna, the grouper and octopus collaboration, Percy using his tools for opening clams, the moray and octopus hunting crabs, the deep sea brine pools...

I watched the episodes so many times as they came together I now sometimes dream in Blue Planet 2 world. I think the passion, strong messages and obvious love for nature that Sir David Attenborough injected into the final episode are also a highlight. We were so lucky to have him delivering the episodes in such inimitable style.

I think science should be 100% objective, and so science fact should be unequivocal, repeatable, non-biased and grounded in strong evidence. Science should also permeate society which means we should work with governments, industry, policymakers and skeptics as well as engaging with conservation agencies and pressure groups. We should be the rational, balanced, and naturally cautious foundation for the debate, and work with the media to spark the conversation but not lead a movement.

What we chose to do in our spare time is personal choice. For example, I am a scout leader and am organising a beach clean next year, and will use this event not only to showcase marine issues but also to gather valuable data for my colleagues and for the Marine Conservation Society.

We are having a devastating effect on some parts of the oceans. Examples include overfishing populations of slow-growing fish, trawling the seabed where corals, sponges, and other slow growing animals live, dynamite and cyanide fishing, smothering habitats with sediment in areas where we have cleared land up to the river edges, etc. But ocean ecosystems are resilient to a degree, as the ocean environments have evolved through natural disturbances, such as sea level changes, cyclones and coastal flooding, which is why we see recovery in areas where local management is improved. The media reflects our uncertainty about the future, where we can predict potential devastation but also still perceive a future where the oceans are healthier than today.

Underwater soundscapes are made up of three elements:

Biophony - this is the sound made by all the animals in the area, including whale song, fish chorusing and individual communication sounds, invertebrate communication (lobsters, snapping shrimp, etc.) and accidental sounds (e.g. parrotfish chomping, urchins grazing).

Geophony - this is the non-biological (abiotic) natural sounds that include rain on the surface, breaking waves, wind on the surface, water flowing on the seabed, occasional subsea earthquakes

Anthrophony - this is the man noise of ships, motorboats, offshore construction, seismic surveys using airguns, wind farm turbines, navy sonar

So it depends where we are as to how much we can detect individual fish sounds, but with our hydrophones (detecting pressure) and accelerometers (detecting particle motion), we can identify many individual sounds and patterns in fish vocalisations.

The combination of ocean warming over the past 40 years, and several intense El Niño events has led to mass bleaching and subsequent death of many coral reefs around the world. Bleaching occurs when corals, which are animals, eject the plant-like cells from their tissue in unseasonably warm periods, thus removing their main source of energy and causing their appearance to turn ghostly white due to their calcium carbonate skeleton becoming visible.

Bleaching has caused up to 95% mortality in some areas, degraded the reefs I know intimately on the Great Barrier Reef, and raised the question whether reefs will survive (as we know them) through the 21st Century. While reefs can recover over time, particularly if they are not isolated, near deeper water corals that can survive bleaching, and are not overfished, the current trend of bleaching occurring more frequently is worrying. This suggests we need to do what we can to reduce the trend in global warming, by reducing CO2 (energy and transport) and methane (animal farming) emissions.

The Blue Planet 2 team include some amazing researchers that scour the scientific literature, build relationships with hundreds of scientists, and engage with scuba, ecotourism and fishing industries to find the newest, most exciting and sometimes surprising stories. Modern technology allows the teams to monitor animals and locations remotely, building an understanding of when and where things are likely to happen. But animals ad weather are still often unpredictable, so there can be lots of waiting around. The patience of the film crews is quite exceptional.

Some of my work is on predation on coral reefs, which is surprisingly rare, so my students and I have spent many days snorkelling or watching remote video for very occasional predation events to occur. In the warm waters of French Polynesia this can be time-consuming but still very enjoyable, but in the spring in the UK it can be freezing and can test your body to the limits.

During my Masters I worked in the British Virgin Islands in the Caribbean, and became interested in how coral reef fish larvae (days to weeks old) choose where to settle after developing in the plankton. Oceanographers were starting to publish recordings of coral reefs which were full of biological noise, so during my PhD developed some experiments in Australia to test whether fish were attracted by reef noise. I found that all the common families of fish were highly attracted by reef noise, and can use it to find habitat and settle onto reefs.

This work got me listening to the ocean, and 15 years on I now have a superb group of researchers and students working on bioacoustic projects around the world. We are unlocking the language used by fish to communicate, using sound recordings to explore and monitor whole ecosystems, and assessing and developing ways to reduce impacts from underwater noise pollution generated by human activity. We are still only scratching the surface of this fascinating dimension of life underwater, which makes it challenging but exhilarating as a field to work in.