A Life History Review for Red Snapper in the Gulf of Mexico with an Evaluation of the Importance of Offshore Petroleum Platforms and Other Artificial Reefs

Red snapper management in the Gulf of Mexico: science- or faith-based?

“…Once small juveniles settle to the bottom, there appears to be a spike in rates immediately after settlement for many species (see Able et al 2006 for review), followed by rapid decline in rates thereafter. While no estimates of mortality rates for planktonic red snapper exist, recent work on young juveniles show that Ms of age-0 snapper are high (M = 0.98-3.7 year -1 ) during and following settlement on sand and mud substrates, and may increase when the density of red snapper recruits increases (Rooker et al 2004;Szedlmayer 2007;Brooks and Powers 2007;Wells et al 2008b;Gazey et al 2008;Gallaway et al 2009;SEDAR 2009; M = 2.0 year -1 was used for model projections in the 2009 red snapper assessment update). At some point cohort biomass ceases to decline, when increasing biomass via growth is equivalent to biomass lost via mortality (G = M).…”

“…Other post-settlement factors can significantly modify recruitment patterns and year class success, and it is conceivable that availability of adult habitat can been limiting for species that require specific substrates to complete their life cycle (Winemiller and Rose 1992). The availability of low-relief, natural habitat for post-settlement red snapper (ages 0 and 1) has been suggested to be limiting (Gallaway et al 2009) because the numbers of age 0 and 1 red snapper have been poorly correlated, suggesting that densitydependent mortality is occurring sometime early in the second year of life. However, age-1 red snapper are considerably more vulnerable to shrimp trawls than age-0s because of mesh sizes used by shrimp trawlers (Gallaway and Cole 1999), making it difficult to draw strong inference about the role of low-relief natural habitat and its availability (see below) in the shallow Gulf as it relates to the numbers of juveniles that ultimately recruit to higher relief natural and artificial reefs.…”

“…In this case, mortality is thought to be density-dependent (Forrester 1990;Holbrook et al 2000;Forrester andSteele 2000, 2004). It should be noted, however, that age-0 red snapper rarely recruit directly to high-relief natural or artificial reefs, rather they settle on sand/mud substrates and transition to more structured habitat with size and age (Patterson 1999;Patterson et al 2005;Wells et al 2008a, b;Gallaway et al 2009). It is this transition that makes them vulnerable to shrimp trawling.…”

A multi-criteria decision approach to decommissioning of offshore oil and gas infrastructure

“…Research has primarily focused on impacts occurring during the active exploration and production phase, for example physical disturbance from drill-cutting discharge (e.g. Jones et al, 2012), and impacts of obsolete structures left in place, for example fish attraction-production (see Gallaway et al, 2009). …”

“…However, we now know that oil structures are capable of developing abundant and diverse marine communities during their production lives, with some structures supporting communities of regional significance (Macreadie et al, 2011). Examples include oil platforms in the northern Gulf of Mexico that support a commercially and recreationally important red snapper (Lutjanus campechanus) fishery (Gallaway et al, 2009), and platforms off southern California that support substantial juvenile populations of a declining rockfish species (Sebastes paucispinis, Love et al, 2006). In other cases, oil structures may provide important habitat to ensure connectivity of populations, as has been speculated for the cold-water coral, Lophelia pertusa, in the North Atlantic (Bell and Smith, 1999).…”