Ecological Archives E094-014-A1

Tal Ben-Horin, Hunter S. Lenihan, Kevin D. Lafferty. 2013. Variable intertidal temperature explains why disease endangers black abalone. Ecology 94:161–168. http://dx.doi.org/10.1890/11-2257.1

Appendix A. Details of thermally matched temperature loggers and field temperature surveys.

We developed biomimetic data loggers to match the thermal characteristics of temperature-logging instruments to that of black abalone. Temperature loggers were deployed to rocky intertidal field sites (Fig. A1) and to all laboratory mesocosms. We constructed temperature loggers using an iButton thermocouple data logger (Maxim Integrated Products, Sunnyvale, CA) insulated within high density paraffin wax (Zog Industries, Carpinteria, CA) stabilized with 5% titanium dioxide (Acros Organics, Geel, Belgium) and contained within black abalone shells. The thermal characteristics of biomimetic temperature loggers were compared with live abalone by constructing curve fits of the product of mass and specific heat for the constructed thermal mimics. The specific heat capacity (cp) of live abalone tissue was approximated as the cp of water (4186 J kg-1 °K-1) and the cp of shell was approximated as 815 J kg-1 °K-1 (S2). We therefore calculated the sum of the products of mass and specific heat capacity for both black abalone tissue and shell as y = 2.15*102 x2.74 + 2.45*101 x3.40; where y is the weighted product of mass and specific heat capacity of live tissue and shell (J °K-1), and x is shell length in mm.

Estimates of the product of mass and specific heat for the biomimetic data loggers were based on the sum of (1) the product of mass and cp of abalone shell at size L, (2) the density (1.16 and 4.23 g cm-3 for paraffin and TiO2 respectively) and cp of the 5% TiO2 paraffin medium (2900 and 711 J kg-1 °K-1 for paraffin and TiO2 respectively), and (3) the iButton thermocouple data logger (m = 19.3 g, cp estimated as that of the 5% TiO2 paraffin medium). We estimated shell volume as a function of black abalone shell length (V = 0.04 L2.88; r2 = 0.99). Fig. A2 illustrates the product of mass and specific heat for the thermally matched, biomimetic data loggers and live black abalone.

We deployed 62 thermally matched temperature loggers at four rocky intertidal sites (Willows Anchorage, 33.96°N 119.75°W; Forney Cove, 34.06°N 119.92°W; Point Sierra Nevada, 35.71°N 121.32°W; and Rocky Point 36.44°N 121.93°W; Fig. A1). Loggers were deployed to intertidal crevices alongside live abalone or to rocky habitats demonstrating previous habitation by black abalone (i.e., abalone home scars were present). Temperature loggers were deployed from fall 2009 to summer 2010 and programmed to record temperature every 30 minutes.

FigA1

FIG. A1. Location of field temperature survey sites.


 

FigA2

FIG. A2. Product of mass and specific heat capacity (Cp) for wax-body temperature loggers (solid line) and live abalone (o), as a function of length.


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