Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda:Palinuridae)

Abstract

Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8–12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa2·s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages.

Seismic air guns damage rock lobster mechanosensory organs and impair righting reflex

“…(a) Animal acquisition, handling, and care Acquisition, handling, and care of lobsters used in this study are as described in detail in Day et al [9] and Fitzgibbon et al [12] and experimental conditions for each experiment, including dates, air gun details, and sample size details, are given in table 1. Briefly, wild-caught female J. edwardsii were obtained from commercial fishermen from several sites around Shoemaker Point, Tasmania, Australia (43°35 0 38.23 00 S, 146°38 0 03.69 00 E).…”

“…The hypothetical source was modelled after field measurements of full-scale arrays [6,37]. The full details of the model conditions are given in the supplementary information of [9]. The hypothetical source was a 3065 inch 3 array operating in three-dimensional mode, comprising two sources operating alternatively, each located centrally 50 m either side of the sail line.…”

“…Comparison of these levels to the modelled full-scale array (electronic supplementary material, figure S4) indicated [44]) at 100-200 m (range due to different estimated maximum values during different experiments). The median cumulative exposures experienced during experiments were equivalent to a set of five seismic lines of the modelled full-scale array with the nearest sail line at 200-500 m range (see [9]). Thus, the exposures experienced during the experiments can be considered to be equivalent to a commercial approximately 3100 inch 3 seismic source passing within 100-500 m range adjacent to the lobsters.…”

“…Compared to vertebrates, the effects of marine seismic surveys on marine invertebrates remain poorly understood [7], with only a limited number of field-based experiments performed to date (see review by Carroll et al [8]). Seismic signals have been shown to have little to no effect on egg development in lobsters [9] or Dungeness crab larvae [10], although zooplankton, largely comprised of crustaceans, including early-life stage larvae, showed substantial mortality following exposure to seismic signals [11]. Adult lobsters show some sensitivity to seismic exposure, with potentially impaired immunity and decreased nutritional condition [12], and more generally to aquatic noise, with exposure resulting in immune response and elevated stress markers in the haemolymph [13,14].…”

Exposure to seismic air gun signals causes physiological harm and alters behavior in the scallop Pecten fumatus

“…Even less is understood regarding the effect of exposure on invertebrates (5). Field-based experiments have rarely been conducted on invertebrates, and the limited available evidence shows little effect on crab and lobster larvae, while zooplankton show a high level of taxa-specific mortality (6)(7)(8). Tank-based experiments simulating exposure have resulted in high levels of damage in several molluscs, including scallop veliger larvae (9) and several species of squid and octopus (10)(11)(12), although it is unclear how laboratory experiments conducted in tanks may translate into the field (13,14).…”