Five reasons we need to think about people this World Oceans Day

Hollie, Rod, Sofia, Will and Mike.


The ocean is the world’s largest and arguably most important ecosystem. Oceans cover 71% of the world’s surface, produce half of the oxygen we breath and absorb about 30% of carbon dioxide emissions. It is estimated to be home to over 1 million species, many of which are yet to be discovered and described by science.

Each year, these ocean assets provide over 170 million tonnes of fisheries and aquaculture products for human use, accounting for 17% of animal protein consumed globally. The total value of these assets is thought to be in excess of US$ 24 trillion, with $2.5 trillion worth of goods and services derived from coastal and marine environments each year. This is higher than the Gross Domestic Product of Italy - the world’s 8th largest economy.

Beyond dollar values, the ocean is a critical source of food and livelihood security for billions of people in poor and developing coastal countries; a place of recreation and relaxation, particularly in the form of coastal and marine tourism; and a source of inspiration for art, culture and scientific discovery.  

Photo: Rodrigo Oyanedel

However, these values are in jeopardy. Around one third of marine species are currently at risk of extinction, according to the UN’s recent biodiversity assessment report. Amongst these threatened species, the futures of charismatic species such as sharks are particularly uncertain. These species losses also threaten the balance of ocean ecosystems, and the good and services they provide to human society. For example, one third of the world’s fish stocks are overexploited, leading to unemployment, malnutrition and severe ecosystem impacts.

The primary causes for these declines are human actions. In particular: overfishing, habitat destruction, and climate change; with these overarching pressures exacerbated by inadequate regulation and management.

As such, this World Ocean’s Day should serve as an opportunity, not only to celebrate the wonder and beauty of the ocean, but to also consider humanity’s relationship with it. In particular, the need to redress the balance in our overuse of marine ecosystems.

In the Zoology Department at the University of Oxford, five researchers from the ICCS group are tackling these problems head on. Hollie, Rod, Sofia, Will and Mike are taking an inter-disciplinary approach to understanding and managing some of the world’s greatest ocean challenges. Together, they give five reasons why we need to think about people this World Oceans Day.


Reason 1: We need to think about people this World Oceans Day, because securing a future for threatened marine species – such as sharks - depends on changing human behaviour


Hollie Booth’s DPhil focuses on mitigating shark fishing mortality through holistic fisheries management, with a particular focus on Indonesia. Sharks and their cartilaginous relatives are one of the world’s most threatened species groups. They are generally slow-growing, long-lived species, which makes them particularly vulnerable to global overfishing.

Photo: Hollie Booth

Practical fisheries management action is required to significantly reduce fishing pressure on sharks, however robust management is largely absent outside of a few developed nations (e.g. Australia, New Zealand, USA). Yet lower-income countries are responsible for the majority of global shark fishing. In these countries, management is complicated by a lack of monitoring and enforcement, and the socio-economic vulnerability of coastal communities, many of which depend on sharks for income, livelihoods and food security. This requires that local socio-economic factors – including economic values, social norms and cognitive biases - are taken in to account when designing management measures.


Hollie’s research aims to better understand and manage these complexities, by combining fisheries and social sciences, to design nuanced management actions that are effective and ethical for sharks and people. To achieve this, she works in collaboration with the Wildlife Conservation Society’s shark program, which aims to ensure that “sharks and rays are effectively protected and sustainably managed, delivering ecological and socio-economic benefits to people and ecosystems”.


Reason 2: We need to think about people this World Oceans Day, because for the ocean to thrive, fishing communities have to become ocean stewards.


Rodrigo Oyanedel’s DPhil thesis looks at one of the most challenging problems in securing a future for the ocean: illegal fishing. Although common in all of the seas, illegal fishing is a tricky problem since its misunderstood and intricate to study. Its elusive nature makes it a headache for governments, NGOs, international agencies and researchers trying to address it. But one thing is for certain: if not solved, illegal fishing could empty our oceans fast.

Photo: Rodrigo Oyanedel

Rodrigo’s research project is embedded in a country that reached far more into the ocean that into land: Chile. With more than 4,000 kms of coast, Chile sustains large fisheries that employ over 100,000 people directly, with many more dedicated to the transformation and selling of fish. However, this livelihood source is threatened by high levels of illegal and unreported fishing occurring all along the coast in fishing communities. Rodrigo’s research has helped to shed light on this problem, with his estimates suggesting that for some species, legal landing accounts for less than 20% of total landings.

Now, how do we turn the tide on these fishing communities for them to become ocean stewards? One of the basics is to understand why they do the things they do. While it sounds pretty obvious, fishers and supply chain actors’ drivers to comply or not with regulations are not well understood. Rodrigo’s DPhil will draw approaches and methods from sociology, criminology, economics and environmental sciences to address this knowledge gap. It is only through a better understanding of the problem of illegal fishing that sound solutions can be proposed. Rodrigo expects his research will help Chile to have a thriving ocean, with fishing communities as stewards.


Reason 3: We need to think about people this World Oceans Day because humans are building new marine ecosystems and we can harness their potential for conservation.


Sofia Castelló y Tickell is focusing her DPhil research on human-made reefs (HMRs) – hard, persistent structures placed in the ocean by humans. Human-made reefs may be created accidentally, as in the case of shipwrecks, but also for purposes such as fishing, coastal engineering, tourism, conservation and coral restoration. They are increasingly common and may present opportunities for conservation, but information on the location, biodiversity and social uses of these novel marine ecosystems is severely limited in comparison to “natural” coral or rocky reefs.

Photo: Sofia Castelló y Tickell

Sofia’s work is based on the island of Cozumel in Mexico, which contains a wide range of human-made reefs including 18thcentury shipwrecks, modern artistic sculptures, infrastructure, fishing traps and custom-built concrete modules for coral restoration. She uses social research methods to interview stakeholders such as archaeologists, fishers, scientists and tour operators, and ecological research methods to assess the diversity and abundance of associated fish, invertebrate and benthic communities.

By gaining a better understanding of the social and ecological dimensions of human-made reefs, we hope to identify and collaboratively act on conservation opportunities in a changing ocean.


Reason 4: We need to think about people this World Oceans Day, because nature and people can no longer be disentangled.


Mike Burgass notes that a key mission for conservation is no longer merely protecting biodiversity in its purest form but allowing for the sustainable use of nature and the fair and equitable sharing of its benefits. Ultimately this is about understanding the impacts of actions and navigating trade-offs to ensure both people and nature are able to thrive. Mike’s PhD research explores how we use data and indicators to better understand these issues in marine systems.

Last year, Mike conducted the first assessment of ocean social-ecological systems in the Arctic. The results showed the Arctic is sustainably delivering a range of benefits to people, but with room for improvement in all areas particularly tourism, fisheries, and protected places. These results are underpinned by successful management of biological resources and short-term positive impacts on biodiversity in response to climate change. The assessment uses data to consider the past and near-term future but does not account for medium- and long-term future risks associated with climate change, highlighting the need for ongoing monitoring, dynamic management, and strong action to mitigate its anticipated effects.

To grapple with climate change and explore trade-offs between biodiversity and fisheries, Mike worked with the Institute of Marine Research in Bergen, Norway. They used a social-ecological model, Atlantis, to explore how biodiversity indicators from fisheries and conservation responded to different fisheries management scenarios under future climate change. The findings suggest that despite having the same intentions, fisheries ecosystem and conservation biodiversity indicators respond differently to each other under the same scenarios, due to how they are constructed. This means that without proper validation, indicators can potentially give different pictures of the same system to different interest groups, meaning greater integration and understanding of conservation and fisheries management objectives is necessary.


Reason 5: We need to think about people this World Oceans Day: Because in order to have effective conservation interventions that work for people and nature we need to embrace interdisciplinary research that incorporates fishers’ views from the start.

Bycatch is the non-target, discarded portion of fish catch and it is one of the major conservation issues in fisheries today. It can affect all types of marine biodiversity but it’s particularly problematic for species such as sea turtles, marine mammals, sharks, rays, and corals, as they can be slow to rebound from fishing impacts. Will Arlidge’s DPhill research is investigating innovative ways to reduce bycatch using a small-scale fishery system in northern Peru as a case study. His thesis topic draws inspiration from biodiversity mitigation, an incentive-based approach to conservation which has been widely applied in terrestrial systems, as well as social network analysis techniques often employed in behavioural biology.

Photo: Rodrigo Oyanedel

One of Will’s projects is seeking to understand how information relevant to a community co-management scheme that is currently being trialled in the northern Peru fishing system flows between fishers and how we might be able to use that information to inform the expansion of the scheme to the wider fishing community. The idea of the community co-management approach is to get participating fishers to put some bycatch reduction technologies on their gear and boat and undertake training in ways to reduce the harm done to turtles captured in their nets when releasing them. Will has undertaken a social network analysis that maps how information about turtle bycatch and other information contexts that relate to fishing flows between fishers in the community. He has found some interesting differences in how turtle bycatch information is shared compared to all the other types of fishing related information assessed. This research can help inform the not-for-profit that is undertaking the trial co-management scheme how fishers perceive turtle bycatch and thereby inform intervention design in future.


Research at the nexus of natural and human behavioural sciences is where exciting and innovative ideas can form, and if the challenge of achieving sustainable fisheries is to be achieved, furthering interdisciplinary research that involves fishers from the start of each intervention’s design, is an ideal way forward.

We need to think about people in this World Ocean Day. The intrinsic value of the ecosystems that the Ocean sustains and nurture cannot be underestimated or ignored. However, it is crucial that we also realize how much value we, as humans, derive from the ocean. Protecting the blue section of our planet is a mission that needs no more delay. We deeply depend on it for our existence. Our efforts, either through protecting charismatic species, or ensuring the provision of ecosystems services, are only examples of the challenges that we, as a society, need to face and think about. The disappearance of species or the overexploitation of fisheries cannot continue to be simple wake-up calls. We need a transformation in the way we relate with our Oceans; one where we sustainably derive benefit from it but never forgetting how much we need the Ocean to thrive so we can thrive as a species too.