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Below you will find a brief description of my research and conservation interests, along with some of the papers we have published on these topics. For further information on the lab, papers, students and projects go to 

Research and Conservation

Spatio-temporal patterns of recruitment in littoral populations of benthic invertebrates

 

Astronomical cycles (which are responsible for tides, the alternation of day and night and the seasonal cycle), oceanographic circulation (wind- and density-driven currents, fronts, internal tides) and the particular characteristics of coast lines (orientation relative to atmospheric circulation, width of the continental shelf, presence of capes, bays and rivers) interact in multiple and complex ways. In some cases these interactions result in recurrent oceanographic structures and processes that concentrate and advect planktonic organisms. Which are the main factors that control marine larval supply to coastal populations, and how they work together with larval behaviour, is the main object of this research line.

Interactions between larval behaviour and physical forcing controlling the dispersal of marine invertebrates

 

Larvae of decapod crustaceans are relatively powerful swimmers. These larvae are capable of vertical migrations along water columns of several tens of meters, in synchrony with the tidal and diel cycles. The rate, direction and amplitude of swimming may be controlled by internal clocks, or respond directly to exogenous stimuli. The interactions of swimming behaviour with recurrent components of marine currents result in predictable mechanisms of larval dispersal and recruitment that we wish to understand. In coasts subjected to upwelling, vertical migration may even constitute a mechanism to avoid wastage of larvae from coastal waters.

 

Connectivity of local populations of littoral invertebrates

 

Most benthic invertebrates and fishes have a larval phase in their life cycle that develops in the plankton for weeks to months. The existence of a larval phase has advantages and disadvantages. Some of the former are a greater dispersal potential, increased recolonization probability following local extinctions, and reduce competition with conspecifics. Among the drawbacks are a greater vulnerability to predation and the failure to find a suitable habitat for settlement and metamorphosis, which are responsible by most of the high mortality rates larvae suffer. The trade-offs between these factors pose interesting evolutionary, physiological and ecological problems. The duration of the planktonic life also bears on the dynamics of the populations and on the management of resources because, all else being equal, the longer the larval phase the higher should be the dispersal radius and the spatial scales of exchange of individuals among local populations. The consequence is that the dynamics of local populations depends on processes that take place at other local populations.

Trophic interactions between benthic microalgae and herbivores regulated by daily and tidal cycles

 

Tidal flats represent a large proportion of the total area of estuaries and coastal lagoons. In these systems, microphytobenthos (MPB) represents an important source of organic matter, which may account for up to 50% of total primary production. A large, but unknown, part of this production is consumed by grazers of the macrofauna, which channel this production to the higher trophic levels. Hydrobia ulvae is small a herbivorous gastropod that displays a daily feeding rhythm, which is believed to be linked to vertical migrations of the microalgae along the first few millimetres of the sediment surface. How is the grazing activity of Hydrobia connected to the cycle of availability of MPB and to the tidal and diel cycles, and how much of the MPB biomass is ingested by Hydrobia, are questions under investigation.

Assessment of production of artisanal shellfish collection

 

Harvest of crustaceans, molluscs and polychaetes by artisanal methods are at the base of several traditional fisheries in Portuguese estuaries and lagoons. These fisheries have a high social importance, because they often constitute the main source of economic income for families; many of the target species are highly valued and are exported from the areas of origin. However, little is known on the level of production of these fisheries, on their impact on the stock, and on the consequences for the ecosystem of trampling and digging of the mudflats. We have developed simple techniques that may be used for routine assessment of production of these fisheries, and are applying them to several components of the artisanal and sport fisheries of the Ria de Aveiro.

Marine Protected Areas

 

One of the international programmes that recognizes the importance of nature conservancy, and actively works towards social and economic development based on the preservation of biodiversity and of ecosystem functioning, is the UNESCO Man and Biosphere Programme, through the World Biosphere Reserves Network. We have worked with the Municipality of Peniche and the Instituto de Conservação da Natureza e Florestas, Portugal, to prepare the application of the Berlengas Archipelago to the Biosphere Reserves Network, which was approved by UNESCO in July of 2011.

 

We are also actively engaged on basic research to support decision-making on the management of Marine Protected Areas. Protected Areas (MPAs) provide a buffer against acute and diffuse environmental disturbances, by protecting different levels of biological organization (genes, species and habitats) and of ecological processes (biogeochemical cycles, trophic web flows, reproduction and population replenishment). Currently, there is a wide consensus among scientists and managers of the marine environment that networks of MPAs are one of the most effective tools to protect the functioning of marine ecosystems and of the services they provide. In this line of research we are mostly concerned with connectivity among the protected areas, and among these and the remainder of the ecosystem, trying to understand how population connectivity contributes to the resilience of the network.

Biogeochemical modelling
 

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