Marine biodiversity in space and time

My research interests have long focused on the interaction between people and marine biodiversity, at a regional to global scale. I am interested in how patterns of marine biodiversity arise, how hotspots of high species richness are formed and maintained. On the more applied side I have been tracking changes in marine biodiversity over time and space, with some emphasis on large marine predators such as sharks, tuna, billfish and whales. I am keen to understand what forces these changes, and what the relative contribution is of human-induced versus natural variation. A lot of my work has focused specifically on the impacts of fishing and climate change, and how they may interact in contemporary ecosystems. From this basis of understanding my students and I try to devise management solution that can help to conserve and restore marine biodiversity worldwide.

The Northwest Atlantic Ocean (NWA) is home to six baleen whale species that are becoming threatened by increasing human pressures, such as fishing and vessel activity. Hannahs research involves determining where these harmful human and baleen whale interactions are likely to take place in the NWA, and how climate change may affect the distribution of these interactions. Hannah is also very passionate about science communication and is involved in many initiatives to help make ocean science and literacy more accessible. 

The unhalted expansion of industrialized fishing fleets has exerted huge pressures on the sustainability of marine megafaunas, mostly in case of large chondrichthyan species comprising of sharks, rays, skates and chimaeras. There are about 1041 chondrichthyans living in the world oceans and one-quarter of these species are threatened according to IUCN Red list criteria. This is mainly due to overfishing, as sharks are often killed for their valuable fins (‘shark finning’) when caught as bycatch, as well as targeted for their meat, oil and other products.Shark finning coupled with 18-fold increase in relative fishing pressure, has reduced sharks and rays’ populations (collectively referred as sharks) by 71% since 1970.As a result, shark finning has been banned in many jurisdictions since the 2000s; however, despite the anti-finning legislations within many national jurisdictions and its violation of the UN FAO’s Code of Conduct for Responsible Fisheries, shark finning continues in many areas. Consequently, there exists little motivation to reduce shark catch and bycatch, while a lucrative shark fin market still prevails in some nations due to weak enforcements and high monetary incentives associated with the fin trade.

My master’s project aims to evaluate how the changes in anti-finning legislation at the Regional Fisheries Management Organizations (RFMO) and country level affected the incidence of finning, and total shark mortality over the last 20 years.

Climate change is already affecting marine ecosystems and shifting species from their historical ranges into previously unsuitable and sometimes poorly protected environments. The Northwest Atlantic is an ideal region to study ocean change because of its more rapid rate of warming. My research aims to assess climate change effects as reflected in fisheries catches of the NW Atlantic Ocean, including both Canadian and US waters, using the mean temperature of the catch (MTC) index. It ultimately aims to inform future fisheries management strategies about regional and transboundary shifts in species and catches, so that management can adequately respond and adapt to the challenges of accelerated environmental and ecosystem change.