Re-examining the relationship between invasive lionfish and native grouper in the Caribbean

Abstract

Biotic resistance is the idea that native species negatively affect the invasion success of introduced species, but whether this can occur at large spatial scales is poorly understood. Here we re-evaluated the hypothesis that native large-bodied grouper and other predators are controlling the abundance of exotic lionfish (Pterois volitans/miles) on Caribbean coral reefs. We assessed the relationship between the biomass of lionfish and native predators at 71 reefs in three biogeographic regions while taking into consideration several cofactors that may affect fish abundance, including among others, proxies for fishing pressure and habitat structural complexity. Our results indicate that the abundance of lionfish, large-bodied grouper and other predators were not negatively related. Lionfish abundance was instead controlled by several physical site characteristics, and possibly by culling. Taken together, our results suggest that managers cannot rely on current native grouper populations to control the lionfish invasion.

Native grouper indirectly ameliorates the negative effects of invasive lionfish

“…Mesocosm experiments have shown little effect of native grouper presence on lionfish behaviors (Morris 2009, Raymond et al 2015. Furthermore, it has been widely debated whether mesopredators such as groupers actually function as biocontrol for invasive lionfish (see Mumby et al 2011 and subsequent responses by Hackerott et al 2013 andValdivia et al 2014). However, Pusack (2013) reported that Nassau grouper appeared to reduce the effect of lionfish predation on native reef fish abundance.…”

Invasive lionfish increase activity and foraging movements at greater local densities

“…At the same time, there is wide variation in lionfish densities within their invaded range, owing in part to differences in the length of time since establishment (Ruttenberg et al 2012, Dahl & Patterson 2014, removal efforts (Frazer et al 2012, de León et al 2013, and abiotic site characteristics including depth and exposure to strong currents and wave surge (Whitfield et al 2007, Anton et al 2014. In contrast, invasive lionfish populations are likely unaffected by potential predators (Hackerott et al 2013, Valdivia et al 2014, but see Mumby et al 2011) or interspecific competitors (Albins 2013), especially given that native predators are severely depleted throughout much of the Caribbean (Paddack et al 2009, Stallings 2009). …”

Lionfish: a major marine invasion

“…Native predators are apparently de - terred by the unusual shape, cryptic coloration, and venomous spines of lionfish, although there is debate regarding whether large native groupers are a major threat to the invader (Mumby et al 2011, Hackerott et al 2013, Valdivia et al 2014. Few parasites attack invasive lionfish (Sikkel et al 2014), native mesopredators appear to be ineffective competitors (Albins 2013), and even highly territorial damselfish do not chase them (Kindinger 2015).…”