Thais Nogueira

Political Assistant

Part of Speakers' Corner

22nd May 2015 Brasilia, Brazil

Seahorses: ‘flagships’ for biodiversity conversation – Guestpost by Dr Lucy Woodall

22 May marks the International Day for Biological Diversity (IDB), a day to increase understanding and awareness of biodiversity issues. The theme for 2015 will be ‘Biodiversity for Sustainable Development’ to reflect the importance of a new set of Sustainable Development Goals (SDGs) being developed as part of the UN post-2015 development agenda and the relevance of biodiversity for the achievement of sustainable development.

Oceans cover 70% of the Earth’s surface area, forming the largest habitat on Earth, while coastal areas contain some of the world’s most diverse and productive ecosystems, including mangroves, coral reefs, and sea grasses. Brazil’s coastline measures 7,491 km, making it the 16th longest national coastline in the world, and the country also has the greatest biological diversity in the world. With that in mind, we invited Dr. Lucy Woodall, scientific associate at the Natural History Museum and an expert on seahorses, to explain to us a little bit about these beautiful creatures present in Brazilian waters.

Jaap van Duivjenbode/Guylian Seahorses of the World (courtesy of Project Seahorse)

Growing up on the coast of the UK I thought I knew all amazing creatures that lived in the cool sea waters, until one day…. while SCUBA diving, I saw a seahorse for the first time. Fifteen years on, after completing my PhD on this amazing family of fish, and conducting research as a marine biologist at Natural History Museum in London, I am excited to share the special aspects of a seahorse’s life and how these fish are great flagship species for biodiversity conservation.

Seahorses, although they don’t have the conventional fish shape, are fish. They have a small dorsal (back) fin to move them along and pectoral (side) fins to rotate; and they possess a prehensile tail, which they can use like monkeys to hold on to objects. This tail is especially important when they live in waters that have high current flow, such as in estuaries, when they will hold onto objects and wait to food to go past them.


From the seahorses we have studied in the wild, most species appear to be monogamous, at least within one breeding season. This means that the same male and female pair, will reaffirm their connection by performing pair-bonding behaviour every morning. This is like a dance on the seabed.

Good fathers

The most well-known thing about seahorses is that they have an unusual mating system. Females give their eggs to the male, he fertilizes them and they remain in his brood pouch for a few weeks until he gives birth. While in the brood pouch he cares for them, ensuring the right nutrients and oxygen levels. Seahorses typically have about 100-200 young in a brood. When they are born they look like miniature adult seahorses!


There are direct and indirect threats for seahorses. Like all marine species, they have optimum conditions in which they can survive, conditions can change due to pollutants, coastal development or climate change. Seahorses are targeted fishery for use in traditional medicines, as souvenirs and as aquarium fish. They are also caught accidental in fishing nets, particularly shrimp trawl nets.

Seahorses are often considered flagship species for marine conservation, this is because they are a charismatic and easily recognisable fish that lives all over the global, in some of the most endangered habitats such as seagrass, mangroves, coral reefs and estuaries. Therefore as we say in Project Seahorse, ‘Saving the seahorse means saving our seas’. The greater the amount and type of habitat we can conserve the great the biodiversity of our planet.

Around the Brazilian coast three species of seahorse can be found. One of these species Hippocampus patagonicus, was only recent distinguished from Hippocampus erectus as a separate species. It can be hard to tell different species apart because seahorses can change colour and pattern to match their habitat, and so these characteristics can’t be used in identification assessments. In addition seahorses appear to change other aspects of their body shape such as the size of skin filaments that can grow along their body. Much of our knowledge about the other species Hippocampus reidi, has come from fishers who have reported declines in populations, revealing the importance of working with local communities.

In summary the seahorses around Brazil are great examples of how traditional knowledge can be integrated with scientific research to make biodiversity assessments.

Dr Lucy Woodall

For more information about the UN Day for Biological Diversity visit

Click here for more information about biodiversity at the London Natural History Museum

About Thais Nogueira

Thais joined the Embassy as Political Assistant in May 2013 to work on Foreign Policy issues. Before joining the UK Embassy, she worked for CEBRI, a Brazilian think tank, and…

Thais joined the Embassy as Political Assistant in May 2013 to work on Foreign Policy issues. Before joining the UK Embassy, she worked for CEBRI, a Brazilian think tank, and was Guest Researcher at SWP, a German think tank. She is interested in Global Governance, Brazilian Foreign Policy and Peace-keeping issues. She lived in Rio de Janeiro, Cairo, Bonn, Berlin and now enjoys Brasilia.