Meeting Abstract
To learn which animals were spawning and the physical correlates of embryo release by adults, we sampled coastal plankton in time series of 72+ consecutive days in each of years, 2014 to 2016 (Jan – mid March). Pump samples were sorted live; distinct phenotypes were counted; and vouchers for these were barcoded (COI or 16S) and identified, when possible, by blasting sequences in Genbank and Bold databases. Lecithotrophic embryos of chitons, gastropods, feather duster worms, several other polychaetes, hoplonemerteans, and other invertebrate taxa were found. Many of the identified taxa were from littoral depths including rocky and sedimentary habitats. Ocean conditions varied tremendously between years as did total embryo abundance. 2014 was a ‘normal’ year, with several storms that brought downwelling favorable winds, large waves, and drops in salinity. In 2014, spawning tended to occur in association with large waves, higher temperature, and lower salinity. 2015 was strongly affected by the warm water ‘blob’, with high water temperatures (11-13C), and few storms with large waves. While some species spawned during large wave events, lecithotrophic embryos were 10 to 100 times less abundant in 2015 and 2016 compared to 2014. 2016 was a strong El Nino year; temperatures were again high (11-13C), but the ocean was consistently rough (only 2 days with waves < 2m). In 2016, 3 of 5 spawning events were associated with large waves, but many days with large waves did not have spawning events. Over the 3 yrs, a number of taxa consistently spawned only during some but not all large wave events. One hypothesis for gamete release during large wave events caused by storms is that it leads to localized retention of short-lived larvae. Our 2014 data set is consistent with this hypothesis, but the great variation among years suggests others factor play roles in eliciting embryo release.
