Mark A. Albins

Worst case scenario: potential long-term effects of invasive predatory lionfish ( Pterois volitans ) on Atlantic and Caribbean coral-reef communities

The Pacific red lionfish has recently invaded Western Atlantic and Caribbean coral reefs, and may become one of the most ecologically harmful marine fish introductions to date. Lionfish possess a broad suite of traits that makes them particularly successful invaders and strong negative interactors with native fauna, including defensive venomous spines, cryptic form, color and behavior, habitat generality, high competitive ability, low parasite load, efficient predation, rapid growth, and high reproductive rates. With an eye on the future, we describe a possible “worst case scenario” in which the direct and indirect effects of lionfish could combine with the impacts of preexisting stressors—especially overfishing—and cause substantial deleterious changes in coral-reef communities. We also discuss management actions that could be taken to minimize these potential effects by, first, developing targeted lionfish fisheries and local removals, and second, enhancing native biotic resistance, particularly via marine reserves that could conserve and foster potential natural enemies of this invader. Ultimately, the lionfish invasion will be limited either by the lionfish starving—the worst end to the worst case scenario—or by some combination of native pathogens, parasites, predators, and competitors controlling the abundance of lionfish.

Threatened fishes of the world: Epinephelus striatus (Bloch, 1792) (Serranidae)

Common name: Nassau grouper. Taxonomy: Groupers (Epinephelus, Mycteroperca, etc.) will likely move to the newly resurrected Family Epinephelidae based on Smith and Craig (2007). Conservation status: Listed as endangered (A2ad) by IUCN, threatened in US and Mexico by AFS, a species of concern by NMFS, and overfished by the CFMC, SAFMC and GMFMC (Sadovy and Eklund 1999; Musick et al. 2000; Cornish and Eklund 2003). Identification: Typically has buff ground color, with 5 dark bars, black saddle at caudal peduncle, row of black spots below/behind eye, dark “tuning fork” mark from upper jaw to top of head (Fig. 1a). May rapidly assume one of three alternate color phases including bicolored (Fig. 1b), whitebellied, and dark. Max length, 122 cm TL; max weight, 23–27 kg. GR, 8–9+15–17; D, XI+16–18; A, III+8; P, 17–19 (Heemstra and Randall 1993; Sadovy and Eklund 1999). Distribution: Bermuda, Florida, Bahamas, Yucatan, throughout Caribbean, rare/transient in Gulf of Mexico. Habitat and ecology: Shallow (0–130 m), insular, clear waters with coral, rocky, or artificial substrate. Juveniles inhabit back-reef macroalgae, coral, and seagrass beds. Generalist, benthic predators of fishes, crustaceans and mollusks. Predators include conspecifics, sharks, and barracuda. Reproduction: Gonochoristic with potential for sex change (Sadovy and Colin 1995). Max life span ca. 29 yrs. Sexual maturation at 4+ yrs. Forms large (tens of thousands of individuals) annual spawning aggregations at specific times/ locations (Smith 1972). Threats: Historically common and important fisheries species. Severe declines across range due to overfishing, especially on spawning aggregations (Sadovy and Eklund 1999). Environ Biol Fish (2009) 86:309–310 DOI 10.1007/s10641-009-9512-5

Biodiversity effects of the predation gauntlet

The ubiquity of trophic downgrading has led to interest in the consequences of mesopredator release on prey communities and ecosystems. This issue is of particular concern for reef-fish communities, where predation is a key process driving ecological and evolutionary dynamics. Here, we synthesize existing experiments that have isolated the effects of mesopredators to quantify the role of predation in driving changes in the abundance and biodiversity of recently settled reef fishes. On average, predators reduced prey abundance through generalist foraging behavior, which, through a statistical sampling artifact, caused a reduction in alpha diversity and an increase in beta diversity. Thus, the synthesized experiments provide evidence that predation reduces overall abundance within prey communities, but—after accounting for sampling effects—does not cause disproportionate effects on biodiversity.

Can humans coexist with fishes

Deciding which textbook to assign to students is often a very difficult decision. A textbook should offer more than just a synthesis of information, it should inspire curiosity, cause one to reflect, and provide a framework for making decisions. Most reviews reflect a single opinion, sometimes based on personal preferences. What is missing from most reviews is an assessment of how a book affected students. We approach this book review differently. We present separate reviews by the instructors and the students participating in a graduate seminar on Fish Conservation. The class format was a mixture of guest lecturers and group discussion. Students were required to write critical comments about each chapter of the book. They understood that they would be co-authors on this review and critical assessment was necessary. The presumption is that similarities between two reviews suggest consensus, but that differences reflect honest differences of opinion as well as differences in background and experience.