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Survival and growth of juvenile hatchery-reared spotted seatrout, cynoscion nebulosus, stocked into rearing ponds at 2 and 9 days post-hatch
Of concern to recreational fisheries is the growth and survival of hatchery-reared sport fish released for stock enhancement purposes. This study was conducted to evaluate the effect of water quality/source on growth and survival of larval spotted seatrout (Cynoscion nebulosus) reared in captivity. Trials were conducted both indoors under controlled conditions and in outdoor tanks. For the indoor trials, seatrout eggs were stocked into replicated (n = 4) 83-L tanks at 50,000 eggs/tank for either 2 or 9 days post-hatch (DPH). During this period, tanks received either filtered seawater, raw seawater, or filtered seawater containing marine microalgae. There was no significant difference (P>0.05) in survival of either 2 DPH (49.95 ± 13.6%) or 9 DPH (30.73 ± 14.2%) larvae regardless of water source. However, a significant difference was observed between the growth rates of 9 DPH larvae, as the larvae in the clear water treatment were significantly smaller (P = 0.01) than the two other treatments. Outdoor tanks (13,000-L) were stocked with 1,500 larvae (2 DPH or 9 DPH) (n = 3) which were reared for 30 days. Growth (TL) and survival rates in the outdoor tanks approximated 1.06 and 1.41 mm/day and 11 and 7.5%, respectively. There was no significant difference (P =0.15) in survival which was similar between the two age groups; a highly significant growth rate difference was shown. Results from this preliminary research indicate that current protocols used to rear juvenile spotted seatrout can be improved by increasing indoor rearing period.Life SciencesCollege of Science and Engineerin
Global COVID-19 lockdown highlights humans as both threats and custodians of the environment
The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness