Functional Response of Larvae to Temperature Changes Tim Chaffey, Satoshi Mitarai, Brian Kinlan, Michael O’Donnell, Mary O’Connor (UNC)

LARVAL TRAJECTORIES ON SST Larvae mostly move along SST contours, due to Geostrophic balance –Particle’s temperature change should be mainly due to mixing and diffusion But, sometimes larvae cross temp contours –Geostrophic balance does not always hold –Leads to significant jump in temperature

TEMPERATURE CHANGE DURING PLD SummerWinter (Temperature change that each settler undergoes during its PLD) Temperature change during PLD (C)

Observed Temperature Eight Year Annual Harmonic

Universal Relationship between PLD and Temperature From Brian’s talk last week -- ln(PLD) = B *ln(T) *(ln(T)) and 0.28 are are derived by averaging all the data across species. B 0 is calculated for each species using the PLD at 15oC.

ln(PLD) = B *ln(T) *(ln(T)) 2

Four Scenarios Constant - Constant PLD (20-40 days) derived from constant temperature (13oC) Start - Constant PLD derived from each particle’s starting temperature. Instant - Fluctuating PLD derived from particle’s present temperature. Avg. - Evolving PLD derived from a running mean of the temperature particle experiences.

Hypothetical PLD- Temperature Dependence Extreme - Mean PLD defined by Mean PLD = 10 o C Mean PLD = 60 days ( o C Mean PLD = 10 days (13-6 days)

Histogram of Settler’s Initial Temperature

Histogram of All Particles Initial Temperature

Extreme StartConstant Settler’s Larval Duration

ConstantStartInstantAvg. Connectivity Matrix - 1

ConstantStartInstantAvg. Connectivity Matrix - 2

ConstantStart InstantAvg. Dispersal Kernel - 2

ConstantStart InstantAvg. Dispersal Kernel - 2

Extreme Case Refresh Compare the Constant case to an Extreme case. –Constant - Constant PLD range (20-40 day) derived from constant temperature (13 o C) –Extreme - Mean PLD defined by Mean PLD = 10 o C Mean PLD = 60 days ( o C Mean PLD = 10 days (13-6 days)

Connectivity Matrix - 1 Revisited Constant Extreme

Dispersal Kernel - 1 Revisited Constant Extreme

ConstantExtreme Connectivity Matrix - 2 Revisited

Dispersal Kernel - 2 Revisited Constant Extreme

Discussion Settling particles are being advected along same water parcel from start to settlement. If P

Dispersal Survival Planktonic larval duration T Larval development (Metabolic rate) Ecology Evolution Conservation PLD = e m *T b 1 + b 2 *lnT