Our Blue Planet

Over the last seven weeks, our Blue Planet II series has focused on the underwater habitats and marine life that live on “our blue planet”, featuring an assortment of captivating creatures, including manta rays, blennies, spinner dolphins, sea turtles, octopus, starfish, and whales; in many different habitats, from the darkest depths, to coral reefs, coastal tide pools, the open ocean, and underwater forests.

Blue Planet II’s final episode, Our Blue Planet, looks to the future and asks, “What will our oceans look like five, ten, twenty years from now?”, examining the ongoing issues of marine pollution, climate change, and other human activity that impacts our oceans. But despite this bleak outlook, there are messages of hope: global organisations, communities, and individuals working together to protect the future of our oceans for all the creatures who call it home. For our last installment of the Blue Planet II series, we reflect on the impact humans have had on the oceans and take a look at what the future has in store for our relationship with the vast blue planet.

• Since 1979, overall ocean surface water temperatures have warmed by 0.133 ± 0.047°C. This has mainly happened in the upper 700m of the ocean, although warming has also been recorded at depths as far as 3,000m.
• Signs of ‘ecosystem distress’ appear at local, coastal, and basin-wide scales. Symptoms include early signs of eutrophication in local and coastal waters, formation of local abiotic zones, reduction in species diversity, reduction in genetic diversity, increased dominance by opportunistic species, and increased disease prevalence. Despite reductions in loadings of some toxic substances in recent years, stress from human activities on the Gulf of Bothnia continues to impact the ecosystem at all spatial scales.
• Landfill and dredging are two of the most harmful coastal activities for coral reefs. This is partly because of direct burial of shallow reefs, but also because sedimentation plumes arising from the activity commonly spread out over several kilometres, blanketing reefs far from the original sites of dredging or construction. The scale of this activity can be enormous: the Saudi Arabian Gulf coast is now nearly two-thirds artificial, as a result.
• Sometimes it’s the little things that can cause the most damage. Those tiny microbeads in your favourite hand soap or body wash can be detrimental to sealife, such as mussels.
  

  

• In tropical coastal ecosystems, mangrove forests are important as feeding, spawning, breeding, and nursery grounds for many marine species. Littorinid snails live on mangrove trees, forming an important component of the mangrove ecosystem and have been used as bioindicators of environmental health and community stress. However, high human population pressure in coastal areas has led to the loss and deterioration of mangrove habitats, and an increase in salt ponds, which have a negative impact on the genetic diversity and genetic structure of Littorinid snails.
• Benthic deep-sea environments are the largest ecosystem on earth. Benthic deep-sea microbes are therefore key drivers of organic matter -remineralisation and nutrient regeneration, influencing biogeochemical cycles and carbon-sink capacity. What impact could climate change have on this special ecosystem?
• Widespread industrialization of the past 300 years has resulted in increased metal pollution from mining, manufacturing, and disposal operations. Seawater contains all naturally occurring metals and the impacts of metal pollution are usually restricted to near the sources. Some metals, however, are highly toxic and can accumulate up food chains, thus concentrating effects by the time humans consume the species, such as mercury building up in tuna. Many reef-dwelling species are used as monitors for toxic metals, and it is commonplace to find ‘hot-spots’ of metal pollution in the vicinity of industrial areas.
• Scientists have found that there have been significant changes to jellyfish populations over the last 50 years due to climate change.
• What are the key challenges in understanding marine socio-ecological systems and how can we attempt to predict the future impacts on these vital environments?
• While nations are responsible for maintaining their shorelines, much of the ocean is left unregulated. Litter, particularly plastics, has been found in far reaches of the ocean, even in the depths of the Mariana Trench. New regulation from the UN aim to decrease the damage to marine ecosystems caused by human activities.
• Controls of industrial wastes have been successful in halting and even reversing some deleterious trends in some regions (such as the Black Sea, Mediterranean, North Sea, and Chesapeake Bay), and most sea areas are now subject to some degree of international agreement for implementing management regimes, however, the degree of effectiveness varies.
• The current geologic period is referred to as the Anthropocene, which stresses the great anthropogenic pressure on the Earth’s atmosphere, geology, and biological diversity, and in the face of threats such as habitat loss, pollution, and expansion, it is easy to feel discouraged. But could the Anthropocene in fact be seen as a good thing, balancing the preservation of the natural world with realistic societal needs and consumption? It is suggested that this optimistic approach is far more effective at galvanizing the general public into action, and encouraging young researchers to move into professional careers in conservation biology than the ‘doom and gloom’ perspective focused on so often.

We hope you’ve enjoyed exploring this fantastic series with us – you can catch up with any posts you may have missed throughout the series below:

Episode 1: One Ocean
Episode 2: The Deep
Episode 3: Coral Reefs
Episode 4: Big Blue
Episode 5: Green Seas
Episode 6: Coasts

Featured image credit: Panorama by pixexid. CC0 Public domain via Pixabay.