Probably/possibly. (But where's the research/study to back that claim up?)
Quite a number of people have posted about observed high lion fish densities at some dive sites where they're not culled. Some things are evident to direct observation. While research to more precisely quantify the population density would be interesting, you can see it for yourself without one.
If we fear reef decimation in the Atlantic/Caribbean, why don't we see it in the pacific where lionfish are even more abundant.
Are they? Without an established system of natural predators, it was my understanding lion fish in the Caribbean can achieve higher population densities. With a little quick Googling, I found
a National Centers for Ocean Coastal Science page (I'm not familiar with them; perhaps someone else can speak to their credibility as a source?) which states:
"Lionfish are capable of permanently impacting native reef fish communities across multiple trophic levels. Energetics modeling and field observations suggest that lionfish are already consuming the majority of forage fish biomass available on some reefs, thus they are crowding out native reef fishes through competitive exclusion.
Lionfish occupy the same trophic position as some economically important species (e.g., snapper and grouper) and may hamper stock rebuilding efforts and coral reef conservation measures. Assessment of these impacts across wide geographic scale and multiple years is needed to quantify the ecological impacts of lionfish. These efforts are critical for coupling lionfish impacts to lionfish densities and evaluation of control and management strategies for lionfish."
Pacific reef ecosystems have long had lion fish as part of the balance of factors driving their equilibrium state. Caribbean reefs have not. Given the numbers of lion fish, the extensive range of habitat type & depth they colonize, their early sexual maturity and massive potential egg production, lack of evident natural Caribbean predators and general carnivore intake, that's reasonably anticipated to be a greater threat than they pose in their native habitat.
A NOAA (National Oceanic and Atmospheric Administration) Fisheries page states:
"Lionfish continue to expand at astonishing speeds and are harming native coral reef ecosystems in the Atlantic, Gulf of Mexico, and Caribbean."
"Adult lionfish are primarily fish-eaters and have very few predators outside of their home range. Researchers
have discovered that a single lionfish residing on a coral reef can reduce recruitment of native reef fishes by 79 percent. Because lionfish feed on prey normally consumed by snappers, groupers, and other commercially important native species, their presence could negatively affect the well-being of valuable commercial and recreational fisheries."
Here's another article, again from a source I'm not familiar with:
Age, growth and population structure of invasive lionfish (Pterois volitans/miles) in northeast Florida using a length-based, age-structured population model
(Sorry, I can't seem to figure out how to shrink the font size down). Just a small piece from that article:
"Lionfish have long venomous spines that deter predation, exhibit rapid growth (
Barbour et al., 2011;
Edwards, Frazer & Jacoby, 2014;
Pusack et al., 2016), mature early and reproduce year-round (
Morris Jr, 2009), and are capable of long distance dispersal during egg and larval stages (
Ahrenholz & Morris, 2010;
Johnston & Purkis, 2011). This combination of life history characteristics has allowed this species to establish and spread rapidly (see
Côté, Green & Hixon, 2013 and references therein for review); lionfish are now among the most abundant predatory fishes in many areas of the invaded range (
Whitfield et al., 2007;
Dahl & Patterson, 2014). Lionfish prey on an array of reef fishes (
Morris Jr & Akins, 2009) and are capable of reducing native fish recruitment by nearly 80% (
Albins & Hixon, 2008) and overall fish biomass by 65% (
Green et al., 2012) with potential cascading impacts on ecosystem structure and function, including extirpations (
Albins, 2015;
Ingeman, 2016). Current evidence suggests that biotic resistance is not likely to present a significant barrier to the lionfish invasion (
Albins, 2013;
Hackerott et al., 2013;
Valdivia et al., 2014) prompting human intervention to help control this species. Harvest is now actively promoted by management agencies throughout the western Atlantic Ocean and Caribbean Sea and has shown promise in reducing densities of this invasive species at local scales (
Frazer et al., 2012;
Albins & Hixon, 2013;
de León et al., 2013;
Green et al., 2014)."
There's plenty of room to question the magnitude of the problem and the pro.s & con.s of potential means of addressing the problem, but I don't think there's much doubt they
are a problem.
Richard.
