Limpet breeding phenology in a changing world
Lead Supervisor: Dr Louise Firth
Location: University of Plymouth, School of Biological and Marine Sciences
Duration: 8 weeks
Suitable undergraduate degrees: Any biological science, conservation or environmental science degree
Climate change is causing the redistribution of life on earth. As the climate warms, many species are experiencing physiological stress, phenological changes (e.g. breeding cycles, migration events) and exhibiting range shifts towards the poles. The UK and Ireland straddle a biogeographic boundary zone with overlapping ‘northern’ and ‘southern’ species and many distributional range limits. This makes the UK an exceptionally interesting place to study the impacts of climate change. Limpets are key structuring agents on rocky shores throughout the UK. Their grazing activity controls the growth of algae and they provide food and habitat for a wide range of organisms. In the UK they are considered sentinels of climate change due to changes in their abundance and breeding patterns. In response to warming temperatures, the northern ‘cold-water’ common limpet, Patella vulgata is declining in abundance1, experiencing a shortened breeding season and fewer are reaching reproductive maturity2. Conversely, the southern ‘warm-water’ black-footed limpet, Patella depressa is increasing in abundance, experiencing an extended breeding season and more are reaching reproductive maturity. Given that P. vulgata has a stronger role in controlling the growth of algae than P. depressa, such changes may have cascading ecosystem effects. Nothing is known about how the other southern ‘warm-water’ China limpet, Patella ulyssiponensis is responding to rising temperatures.
This project will take advantage of existing long-term datasets collected by the late Dr Rosemary Bowman comprising information on limpet breeding cycles (P. vulgata, P. ulyssiponensis 1967-2014) and temperature data (1990-2004) for two locations in northeast England. Some of these data were published in the 1970s and 1980s3-5 but Rosemary continued to collect data long after these publications. This will be combined with breeding cycle data from 2012-2014 and satellite-derived temperature data from 2004-2014. Limpet breeding data contains information on the sex and gonad stage (1-5) of a minimum of 50 individuals of each species that were sampled monthly across the study period. The student will interrogate this valuable dataset to assess patterns of long-term change over time. It is expected that (a) the breeding period would have shifted to later in the year in response to warming temperatures; (b) that P. vulgata would be favoured (i.e. greater numbers reaching reproductive maturity – gonad stages 4 and 5) by periods of cooler weather and; (c) that P. ulyssiponensis would have been favoured by periods of warmer weather. The student will get experience in data manipulation, figure production, statistical analysis and writing – all of which will be beneficial for preparing them for scientific reporting and writing. The results from this research will yield a large dataset that will be published and made available to the public and they will also contribute to the scientific paper that will be written this summer. The student will be listed as a co-author on the dataset and on the paper – both of which will be hugely beneficial to their career.
1 Hawkins et al. (2013). Data rescue and reuse: recycling old information for new concerns. Marine Policy 42:91-98
2 Moore et al. (2011). Phenological changes in intertidal con‐specific gastropods in response to climate warming. Global Change Biology 17:709-719.
3 Bowman & Lewis (1986). Geographical variation in the breeding cycles and recruitment of Patella spp. Hydrobiologia 142:41-5
4 Lewis & Bowman (1975). Local habitat-induced variations in the population dynamics of Patella vulgata L. Journal of Experimental Marine Biology and Ecology 17:165-203.
5 Lewis et al. (1982). Some geographical components in population dynamics: possibilities and realities in some littoral spp. Netherlands Journal of Sea Research 16:18-28.