Larval connectivity along the Oregon coast

Project Title: Realized and Potential larval connectivity along the Oregon Coast Hal Batchelder1, Bill Peterson2, & Jennifer Fisher2 With Contributions from John Osborne (CEOAS Grad. Student) 11 CEOAS, 104 CEOAS Admin Bldg, OSU, Corvallis, OR2 CIMRS, Hatfield Marine Science Center, Newport, OR

Multiple Uses Cape Falcon and Marine Spatial Cascade Head Planning Otter RockMSP in Oregon Cape Perpetua Cape Arago Redfish Rock Inner Redfish Rock Outer

Realized Larval Connectivity (RLC) is the number of observedlarvae that travel from a specific spawning site to a specificdestination site.RLC is rarely known because the numbers of larvae at time andlocation of spawning are not known and matching recruits in aspecific destination site back to a specific site of origin in situ isdifficult; can be done with otolith chemistry, genetics for somespecies.More commonly we estimate (using model simulations):Potential Larval Connectivity (PLC), which is the probability oflarval transport from a spawning site to a destination site.

A Simple Potential Connectivity Example Two Marine Reserves (A & B) providing refuge for Adult Organisms A One type of connectivity is to estimate PLC between A and B over some time interval Δto Δ Δtd T d o A B 1000 0.227 227 o d 1000 0.056 56 But, the real world isn’t simple… BPLC = func {Δto, Δtd , ΔT, T,Ao,Ad}ΔT = func {uv,°T, Mixing, M, Life History, Behavior}T = func {year, day of year}

And, we are interested in more than the connection among reserves… U1Reserves are intended to provide spillover of adults tonearby regions (which can be fished), and so that they Aprovide new recruits to other suitable habitats outsideof the borders of the reserves. Suppose: Mid-summer release of U2d o 1000 individuals from both A and B A Bo d U3 Destination Origin U1 A U2 U3 B U4 Sum A 5 35 63 300 227 10 640 B 0 0 0 24 56 150 230 B More larvae from A recruit to B than do larvae from B Note assumption of equal larval supply at A & B U4

Potential connectivity assumes equal source strength everywhere… U1What if we know that 10X more larvae are produced atB than at A A Suppose: Mid-summer release of U2d o 1000 individuals from A and 10000 A individuals from B Bo d U3 Destination Origin U1 A U2 U3 B U4 Sum A 5 35 63 300 227 10 640 B 0 0 0 240 560 1500 2300 B More larvae from B recruit to B than do larvae from A, or B is largely self-seeding. U4

Realized larval connectivity assumes knowledge of abundances of larvae U 1 produced or recruited (usually)… A These estimates are hard to knowd o through space and time. Instead, A what can we say about realized B connectivity if we know the spatial U2o d and temporal distribution of larvae in the plankton (from net samples)? U3 Can we robustly estimate both the site of origin and the likely destination of meroplanktonic larvae B captured in plankton tows? And thereby construct realized connectivity maps? U4

48° N La Push Observations Washington Queets River • Newport Line biweekly sampling since 1996 (17 years)47° N Grays Harbor • Large-scale Plankton sampling Willapa Bay June and September since 1998 (15 years) Columbia River46° N Oregon • Data we will use: Cape Falcon • Newport biweekly plankton Cape Meares (2009 – 2011) • Large-scale plankton45° N Cascade Head (2010 – 2011) Newport ^ _ Cape Perpetua 126° W 125° W 124° W 123° W

Crab Larvae Barnacle LarvaeCancer magister Zoeae stage I Lophopanopeus bellus Zoeae stage I Balanus crenatus Nauplii and Cyprid Hemigrapsus spp. Pachygrapsus crassipes Megalopae

Realized Connectivity48° N La Push • Using hindcast physics from Washington the data assimilating real-time Queets River Oregon physics forecast model and info on abundance &47° N Grays Harbor distribution of meroplanktonic lifestages of barnacles and crabs Willapa Bay • identify most probable source regions (PDs)46° N Columbia River and dates of larvae Oregon production using Cape Falcon backward time Cape Meares trajectory modeling45° N Cascade Head • identify most likely destinations of larvae Newport using forward time trajectory modeling ^ _ Cape Perpetua 126° W 125° W 124° W 123° W

Outcomes1) Identification of source and probable destinations of larvae using particle-tracking methods, robust physical representations of ocean circulation, and life history information (incl. depth behaviors of larvae).2) Results will provide guidance to monitoring and assessment efforts to characterize the the efficacy of OR MR/MPA network. Identification of gaps that might inhibit successful MR/MPA networks.3) Informal collaboration with CA SG funded PIs (Steve Morgan/Chris Edwards) on similar connectivity project will extend understanding of factors driving larval dispersal, supply and connectivity to most of the CCLME.

Outreach planDissemination of results • Working with Jeff Feldner, we will determine the most effective avenue for communicating our results • Meetings with targeted resource managers, public meetings, etc.HMSC exhibit • We will consult with Bill Hanshumaker on the development of a display about coastal connectivity and marine reserves; it will compliment the existing exhibit on larval dispersal of oysters in Yaquina Bay (Emily Lemagie and Jim Lerczak) • Fall 2012- a static display along with hands-on ‘activities’ will be installed • FY2013- an intern will evaluate the efficacy of our display and will outline deficiencies and ways to better overlap with the existing exhibits • FY2013- improvements to the display will be made and an intern will assist in transitioning from a static display to a video display

Larval connectivity along the Oregon coast

by Oregon Sea Grant

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