COS 87-1 - Marine invasion rates across the tree of life

Wednesday, August 9, 2017: 8:00 AM
E143-144, Oregon Convention Center
Jonathan Belmaker, School of Zoology, Tel Aviv University, Tel Aviv, Israel; The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Israel
Background/Question/Methods

Invasions are one of the most significant agents of biodiversity change. However, studies of invasion have typically focused on single taxa. Attempts to synthesize patters across broad taxonomic groups have been hampered by sampling biased and the lack of standardized methodology. The Eastern Mediterranean is receiving a large influx of Red Sea species has followed the opening of the Suez Canal in 1869. These invasive species make up a large percentage of total species in this region and have substantially modified its biodiversity. This research focuses on this unique 'natural experiment', to understand the underlying correlated of invasion success across the tree of life, taking into account imperfect detection and variability in sampling effort through time.

Results/Conclusions

In this study, we statistically control for potential biases in detection rate and sampling effort to uncover underling invasion rates. By employing this method over a wide range of taxa, we are able to show substantial variation in the rates of invasion. Specifically, taxa can be separated into groups such as fishes, bivalves and algae that are characterized by a fast and increasing invasion rates and groups such echinoderms, sponges and ascidians that have low and constant invasion rates. Across time, we find that most groups present a dip in invasion rate in the late 1960s, a period in which the Suez Canal was closed to marine vessel transport. Across taxa, we find that the best predictor of invasion rates is the date in which the first species of the group was seen in the Mediterranean, with taxa that arrived early characterized by high invasion rates. Other factors such as the number of species in the taxa within the native range or within the Mediterranean were weaker predictors of invasion rates. Taken together, we argue that such inter-taxa comparison can shed light into the main life-history attributes and environmental correlates associated with invasion success.