Artificial light at night does not alter heart rate or locomotor behaviour in Caribbean spiny lobster (Panulirus argus): insights into light pollution and physiological disturbance using biologgers.

Light pollution is a rapidly growing threat to biodiversity, with many unknown or poorly understood effects on species and ecosystems spanning terrestrial and aquatic environments. Relative to other taxa, the effects of artificial light at night on aquatic invertebrates are poorly understood, despite the abundance and integral significance of invertebrates to marine and freshwater ecosystems. We affixed heart rate and acceleration biologgers to adult Caribbean spiny lobster (Panulirus argus), an ecologically, culturally and economically significant species in the western Atlantic ocean, to test the effect of artificial light at night on this species' physiology and behaviour relative to appropriate controls. The experiment was conducted in a simulated reef mesocosm in The Bahamas with incandescent lighting used to illuminate it at 1 lux, approximating light levels offshore of urban areas. In the conditions tested here, artificial light at night was found to have no effect on heart rate or locomotor activity in P. argus. We observed a dissociation between activity and heart rate at both short-term and long-term temporal scales. Lobsters were more active at night and nocturnal activity was higher in trials closer to new moon; however, heart rate did not vary with diel or lunar cycle. There was less than 8% difference between daytime and night time average heart rate despite the average percentage of time spent active almost tripling in nights versus days, to 19.5% from 7.2%, respectively. Our findings suggest P. argus may have some resilience to low levels of light pollution, which warrants further research on aspects of this species' life history, performance and fitness in the face of this potential anthropogenic disturbance.

An appetite for invasion: digestive physiology, thermal performance and food intake in lionfish (Pterois spp.).

Species invasions threaten global biodiversity, and physiological characteristics may determine their impact. Specific dynamic action (SDA; the increase in metabolic rate associated with feeding and digestion) is one such characteristic, strongly influencing an animal's energy budget and feeding ecology. We investigated the relationship between SDA, scope for activity, metabolic phenotype, temperature and feeding frequency in lionfish (Pterois spp.), which are invasive to western Atlantic marine ecosystems. Intermittent-flow respirometry was used to determine SDA, scope for activity and metabolic phenotype at 26°C and 32°C. Maximum metabolic rate occurred during digestion, as opposed to exhaustive exercise, as in more athletic species. SDA and its duration (SDAdur) were 30% and 45% lower at 32°C than at 26°C, respectively, and lionfish ate 42% more at 32°C. Despite a 32% decline in scope for activity from 26°C to 32°C, aerobic scope may have increased by 24%, as there was a higher range between standard metabolic rate (SMR) and peak SDA (SDApeak; the maximum postprandial metabolic rate). Individuals with high SMR and low scope for activity phenotypes had a less costly SDA and shorter SDAdur but a higher SDApeak Feeding frequently had a lower and more consistent cost than consuming a single meal, but increased SDApeak These findings demonstrate that: (1) lionfish are robust physiological performers in terms of SDA and possibly aerobic scope at temperatures approaching their thermal maximum, (2) lionfish may consume more prey as oceans warm with climate change, and (3) metabolic phenotype and feeding frequency may be important mediators of feeding ecology in fish.

Application of Miniature Heart Rate Data Loggers for Use in Large Free-Moving Decapod Crustaceans: Method Development and Validation.

Cardiovascular responses of decapod crustaceans to environmental challenges have received extensive attention. However, nearly all of these studies have been restricted to lab-based experiments; here we describe a methodology that will enable measurement of heart rate (HR) in free-moving decapods in the field. Data storage tag heart rate and temperature loggers (DST micro-HRT; Star-Oddi) were used to record electrocardiograms (ECG) and HR in large decapod crustaceans. These loggers were originally designed for use in vertebrates and must be surgically implanted in the body cavity near the heart in order to function. We adapted these loggers for external use in large decapod crustaceans. The method involved abrading the carapace directly above the heart and placing the electrodes of the logger directly on top of the dermal tissue. The logger was then secured in place with periphery wax. This method negated some of the more intricate operations used for vertebrates. The rapid setup time of approximately 5 min suggested that animals could be easily instrumented in the field and without the use of anesthetic. The logger was calibrated by simultaneously measuring the HR changes of a West Indian spider crab Mithrax spinosissimus with a pulsed-Doppler flowmeter. The data gathered with the two methods showed a tight correlation during an increase in temperature. The loggers were also successfully implanted in a variety of other large species of aquatic and terrestrial decapods. The data obtained showed that the method works in a broad range of species, under different experimental conditions. In each case, the loggers comprised less than 1% of the body mass and would be suitable for use in animals >300 g. All animals survived the attachment procedures and were feeding and active after removal of the loggers. Nearly all previous cardiac measurements on decapods have been carried out in controlled laboratory settings. The use of these loggers will make significant advances in measuring HR in unrestrained, undisturbed animals in their natural environment during extended periods of time and has the potential to lead to novel findings.

Angling into the Future: Ten Commandments for Recreational Fisheries Science, Management, and Stewardship in a Good Anthropocene.

A new geological epoch, the "Anthropocene", has been defined as the period in which humans have had substantial geological and ecological influence on the planet. A positive future for this epoch can be referred to as the "good Anthropocene" and would involve effective management strategies and changes in human behavior that promote the sustainability and restoration of ecosystems. Recreational fisheries hold significant social, cultural, and economic value and can generate many benefits when managed sustainably and thus be an integral part of a "good Anthropocene". Here, we list ten commandments to facilitate persistence and long-term sustainability of recreational fisheries in the "good Anthropocene". This list includes fostering aquatic stewardship, promoting education, using appropriate capture gear, adopting evidence-based management approaches, promoting the concept of resilience, obtaining and using effort data in management, embracing the ecosystem approach, engaging in multilevel collaboration, enhancing accessibility, and embracing optimism. When used singly, or simultaneously, these ten commandments will contribute to the harmonization of sustainable fish populations and angling practices, to create recreational fisheries' "bright spots".