Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Parameters
• Project Information
• Funding

Sizes of Kellet’s whelk (Kelletia kelletii) individuals, defined here as maximum shell length, in populations in the wild were obtained from subtidal benthic surveys conducted by scientific SCUBA divers at kelp forest habitat sites across the species’ biogeographic range and over multiple years. At each site, up to six belt transect population surveys were conducted; within each, divers systematically counted and measured every visible Kellet’s whelk individual, including cryptic individuals in the survey area but not including individuals hidden from sight under the substrate (i.e., non-invasive sampling, avoiding turning over rocks and digging in sand). To increase sample size at some sites, additional systematic surveys were conducted within 10 m of the transect. 

These population surveys were focused specifically on Kelletia kelletii and are hereafter referred to as Kelletia kelletii surveys (KkS). KkS survey data were collected in 2015, 2016 and 2017 from 36 benthic kelp forest sites (5 - 28 m depth), from Monterey Bay, California, USA to Isla Asuncion, Baja California Sur, Mexico. [***CONTENT COPIED OVER BY INFO FROM CORRESPONDANCE WITH C.W.***] Expanded and Historical range sites are differentiated per row within the primary data file. Expanded range sites are along the central California coast north of Pt. Conception (34.4486° N, 120.4716° W), while historical range sites are on the other side of Pt Conception in the Southern California Bight, USA and Baja California, Mexico.

The surveys were conducted during summer months (June through August). Individual whelks were transported to a surface vessel and measured, then transported back to their collection location. Whelk size was measured to the nearest mm using calipers and recorded on dive slates or field notebooks, then transcribed to a datasheet and electronic database in the lab. 

Field data was transcribed to an Excel electronic database in the lab.

NSF Award Abstract:
Where do young marine fish and shellfish come from? This project aims to improve our understanding of how coastal marine populations are connected in space and time. Coastal populations are replenished through the arrival of minuscule larvae that have been dispersed for weeks to months in the open ocean after spawning at remote sites. The combination of the long dispersal period of marine fish and shellfish larvae and the varying ocean currents results in complex patterns of "connectivity" among populations near and far. Identifying these patterns of connectivity is fundamental to marine science and critical for effective fisheries management and conservation, yet it remains an unresolved component of marine ecology. The study species is currently expanding its biogeographic range up the U.S. west coast. By genetically analyzing individuals from across the species' range, including offspring spawned in the laboratory by experimentally-crossed individuals collected in the field from throughout the species historical and expanded range, certain genes can serve to differentiate populations along the coast. The team leverages the statistical power of these geographically-informative genes to assign thousands of young collected in the field to the source populations that spawned them (across the species' range and over multiple years). The team then quantifies patterns of connectivity over multiple years, and tests fundamental hypotheses on the spatial scale, temporal variability, biogeographic patterns, and biophysical drivers of population connectivity. The project trains approximately two dozen U.S. university students in molecular ecology and marine science, as well as creating intellectual linkages among Ph.D.-granting and non-Ph.D.-granting universities. The project also supports further development of a K-12 education program that uses SCUBA diving and videography to teach elementary school students Next Generation Science Standards and train them for careers in science, technology, engineering and mathematics.

Using a kelp forest gastropod and fisheries species (Kellet's whelk, Kelletia kelletii), this project combines genome-wide Restriction site Associated DNA (RAD) loci with transcriptomic loci identified from common-garden laboratory crosses of individuals from the species' historical and expanded range to identify geographically-informative loci that maximize power for individual assignment testing. Leveraging the combined power of these loci, genetic assignment of approximately three thousand recruit samples to 20 putative source populations allows the team to construct three independent years of connectivity matrices and test some of the most fundamental questions in marine ecology, including: 1) Are marine populations open or closed and at what scales? 2) To what degree is the evolutionary pattern of gene flow represented by single versus multiple generations of connectivity events? And, 3) How spatially heterogeneous and temporally variable is population connectivity? Can one year of connectivity data predict anything about the next? Additionally, by focusing on a range-expanding species with common life history traits, the team addresses a number of questions with broad applicability and significant ecological and societal implications: 4) How much is population connectivity influenced by post-recruitment demographic and evolutionary processes? 5) How well-connected are historic- and expanded-range populations? And, of particular relevance to climate change, 6) Are El Nino oceanographic conditions, which are predicted to increase in frequency and intensity this century, driving the poleward range expansion of this coastal marine species? By coupling common-garden experimental crosses to identify maximally-informative transcriptomic loci with genomic RAD analysis of field samples, this project aims to accurately and precisely quantify marine population connectivity in high gene flow species with large population sizes.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.