The Olympia & Pacific Oyster Data Portal

Locations (i.e., "records") of Ostrea lurida (Olympia oysters) and Magallana gigas (Pacific oysters) observed 1602 to 2020 along the west coast of North America. Records are denoted as absent, present, rare (1-100 oysters), or common (>100 oysters) along a 20-m linear stretch of coastline. Also included are hypothesized adult and larval networks and their associated connections.

This geographic dataset was compiled through a project jointly led by the Native Olympia Oyster Collaborative and The Pew Charitable Trusts. It provides the first detailed maps of current and historic distributions of the native Olympia oyster (Ostrea lurida) to inform conservation and restoration strategies, as well as populations of the non-native Pacific oyster (Magallana gigas) along the west coast of North America.

==About the portal dataset layers

1) Ostrea/Magallana (all records, all years, excluding "sensitive" records)

- Ostrea lurida

2) Ostrea lurida (presence only, 2000-2020)

3) O. lurida Adult Networks (minus Salish Sea, 2000-2020)

4) O. lurida Larval Network Connections

5) O. lurida Larval Networks (2000-2020)

- Magallana gigas

6) Magallana gigas (presence only, 2000-2020)

7) M. gigas Adult Networks (minus Salish Sea, 2000-2020)

8) M. gigas Larval Network Connections

9) M. gigas Larval Networks (2000-2020)

==Layer notes==========

=all records - presence only, 2000-2020

Locations (i.e., "records") of Ostrea lurida (Olympia oysters) and/or Magallana gigas (Pacific oysters) observed along the west coast of North America. Records are denoted as absent, present, rare (1-100 oysters), or common (>100 oysters) along a 20-m linear stretch of coastline.

=Adult Networks (minus Salish Sea, 2000-2020)

Hypothesized adult networks, defined as the area within well-defined estuary boundaries (i.e., not on the open coast) within larval networks.

Some of the area within larval networks was located in open ocean (e.g., between estuaries). Therefore, adult networks are defined as the subset of any larval network only within well-delineated estuaries (i.e., not in the open ocean).

For this project, high-resolution estuary boundaries were unavailable for British Columbia, Canada; thus, only larval, and not adult, networks were generated there. Hydrodynamic/current models were not included/analyzed to account for actual travel as that was beyond the scope of this project.

=Larval Network Connections

Distances between hypothesized larval networks based on a 30-km maximum larval transport distance around clusters of 3+ adult oyster records for oysters observed 2000 to 2020 that were indicated as present, rare (1-100 oysters), or common (>100 oysters) along a 20-m stretch of coastline.

Connectivity among larval networks was based on Optimal Region Connections. The output of this analysis measures the shortest, i.e., optimal, distances among networks while accounting for barriers (in this case, the coastline). For each network, we calculated the mean distance to the nearest network to the north and the nearest network to the south as the metric for network isolation (e.g., higher numbers represent more isolated networks).

=Larval Networks (2000-2020)

Hypothesized larval networks based on a 30-km maximum larval transport distance around clusters of 3+ adult oyster records for oysters observed 2000 to 2020 that were indicated as present, rare (1-100 oysters), or common (>100 oysters) along a 20-m stretch of coastline.

These networks encompass groups of sites with adult oysters present that might plausibly be linked through larval dispersal. Larvae can successfully recruit after traveling as far as 75 km if currents are favorable, but 30 km was used as a limit to dispersal by Wasson et al. (2016). They demonstrated that the network size defined by this metric correlated significantly with stability in recruitment (i.e., larger networks had less recruitment failure). For the sake of comparisons between Ostrea lurida and Magallana gigas, we thus considered sites with living adults observed between 2000-2020 and within 30 km of each other to be part of the same larval network.

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Credits: Kornbluth A, Perog BD, Crippen S, Zacherl D, Quintana B, Grosholz ED, & Wasson K (2021, in press). Mapping oysters on the Pacific coast of North America: a coastwide collaboration to inform enhanced conservation. PLoS ONE.

For more information about these data and the methodology used to generate this layer, please contact Dr. Kerstin Wasson (University of California, Santa Cruz, California and Elkhorn Slough National Estuarine Research Reserve) at kerstin.wasson@gmail.com.

To view this geographic dataset in the context of the other layers developed for this effort, please visit The Olympia & Pacific Oyster Data Portal at https://noaa.maps.arcgis.com/apps/View/index.html?appid=a49a0bc8a0764fc799d81f6652b7a13b