Squid are often referred to as keystone species because of their central role in ocean ecosystems. They play vital roles in marine food webs both as prey for many of top predators such as seabirds, dolphins, sharks, and tunas, and as voracious predators of smaller, often deep-water (mesopelagic) fishes and invertebrates. Squid comprise a substantial fisheries resource, both directly as commercial and recreational fisheries, and indirectly as an important food source for many of the fishes consumed by a growing human population. Changes in squid abundances can dramatically impact the ecology of the ocean and fisheries yields. Despite the importance of squid to both ecosystems and economies, there has been little investigation of the effects of ocean acidification (OA) on these taxa. Impacts upon juvenile squid are a primary concern because: (i) early developmental stage animals are highly sensitive to environmental conditions and (ii) their successful early life history growth, behavior and survival are critical to founding future cohorts that support ecosystem food webs and global fisheries. The goal of this work is to quantify how OA conditions impact squid embryo and juvenile development, behavior, and survival. The studies will provide a mechanistic foundation for understanding potential impacts of OA on squid populations. Squid are dynamic organisms, which may now encounter high carbon dioxide and lower pH in areas of ocean upwelling, and measures of these environmental variables will be collected in this study. This research takes an extensive whole-organism approach to understanding OA impacts on squid by examining anatomy, physiology, and behavior of these animals at levels of environmental carbon dioxide and pH encompassing present-day and predicted, future values. These are the first tests to comprehensively examine OA impacts on squid. The experiments are timely in the context of changing ocean conditions, increased pressure on squid fisheries, and preliminary data showing potential OA impacts on squid. Understanding these effects will aid fisheries managers in estimating ecosystem and economic impacts in this and other cephalopod species. Information from this research will be used to engage and educate the general public, who are fascinated by squid biology, about ocean acidification through a summer seminar series at Woods Hole Oceanographic Institution. The research team and the Woods Hole Oceanographic Communications Department will communicate findings from this study to journalists; interact with teachers about this work through existing fellowship programs; construct and convey education materials for grade-school children at a local science school; and develop a squid dissection module for high school teachers entitled "Squid have ears too!"
