Current Projects

Dr Justin Lathlean is a marine ecologist, currently based at Rhodes University, whose research focuses on the thermal biology and demography of intertidal invertebrates across broad and fine spatial scales.

CURRENT PROJECTS

Climate change and primary productivity of intertidal macroalgae

In collaboration with Nessa O'Connor & Mark Emmerson (Queen's University Belfast) 

Macroalgae are important primary producers and habitat formers within coastal systems around the world and significantly contribute to the storage and transfer of carbon across ecosystem boundaries. Despite their importance, however, it remains relatively unclear how their abundances and distributions will change in response to future warming and increased storminess. The aim of this project is to (i) thermally manipulate intertidal macroalgal communities in the field to get a realistic understanding of how future climate change will alter these primary producers and their associated communities, and (ii) undertake latitudinal comparisons of intertidal fucoids to assess how large-scale differences in environmental parameters influence their geographic distributions.

Developing dynamic energy budget (DEB) models for intertidal mussels in South Africa

In collaboration with Morgana Tagliarolo (University KwaZulu-Natal) and Cristian Monaco (Rhodes University) 

Habitat temperatures and food availability are the two major factors that influence the physiological fitness and reproductive success of many ectothermic organisms. By developing dynamic energy budget models this project seeks to understand how large-scale geographic variability in mussel body temperatures and food availability influences current and future abundances, growth rates, reproductive output and survival of the two dominant species of intertidal mussels in South Africa.

Intercontinental comparisons of barnacle recruitment

In collaboration with Prof. Christopher McQuaid (Rhodes University)

A long held paradigm in marine biogeography has been that large-scale oceanographic processes, such as upwelling, exert strong bottom-up control of ecological communities. However, the intensity, duration and frequency of upwelling may vary significantly within and amongst biogeographic regions such that the degree of upwelling at any one site should be placed on a continuum ranging from strong persistent upwelling, to intermittent upwelling/downwelling, to strong persistent downwelling. This project is investigating how differences in the intensity, duration and frequency of upwelling and downwelling influences rocky intertidal communities, specifically barnacle recruitment, across Australia and South Africa.

Geographic variation in the utilisation of biogenic habitats

In collaboration with Prof. Christopher McQuaid (Rhodes University)

Mussel beds provide essential biogenic habitats for many organisms around the world. This project seeks to understand how the biotic and abiotic characteristics associated with mussel beds change along the east, south and west coasts of South Africa.

 

Thermal manipulations and altered species interactions

In collaboration with Assoc. Prof. Todd Minchinton & Russell McWilliam (University of Wollongong)

As rising temperatures are expected to alter the relative abundances of individual species, the strength of interspecific interactions will also change. This innovative experiment manipulates both temperature and species interactions in the field to predict how rocky shore communities will change in the future.

 

Effects of elevated temperature and salinity on mangrove propagule dispersal and estabishment

In collaboration with Assoc. Prof. Todd Minchinton (University of Wollongong)

There has been a considerable amount of research which has shown that elevated sea temperature and salinity alter the dispersal capabilities of marine fish and invertebrate larvae. By contrast, it remains poorly understood whether the same is true for marine plants. This work, which is being led by Assoc. Prof. Todd Minchinton (UoW), investigates whether differences in temperature and salinity during the dispersal stage effects the settlement and establishment of mangrove (Avicennia marina) propagules.  

 

Experimental warming of saltmarsh communities

In collaboration with Assoc. Prof. Todd Minchinton (University of Wollongong)

Saltmarsh communities of southeast Australia are becoming increasingly threatened by the encroachment of mangrove forests. This experiment, which is being led by Assoc. Prof. Todd Minchinton (UoW), uses artificial warming chambers to test the effects of increased temperatures on the establishment and survival of mangrove propagules in saltmarsh communities.