Recent Advances in Data Logging for Intertidal Ecology

Abstract

Temperature is among the most ubiquitous determinants of organism growth, survival, and reproduction. Accurate recordings and predictions of how the temperatures of plants and animals vary in time and space are therefore critical to forecasting the likely impacts of global climate change. Intertidal zones have long served as a model ecosystem for examining the role of environmental stress on patterns of species distributions, and are emerging as models for understanding the ecological impacts of climate change. Intertidal environments are among the most physically demanding habitats on the planet, and excursions in body temperature of ectotherms can exceed 25 • C over the course of a few hours. It is now well-known that the body temperatures of intertidal organisms can deviate significantly from the temperature of the surrounding air and substrate due to the influence of solar radiation, and that their size, color, morphology, and material properties markedly influence their temperatures. While many intertidal organisms are slow moving or almost entirely sessile, for others, behavior can play a significant role in driving vulnerability to temperature extremes. We explore datalogging methods used in intertidal zones and discuss the advantages and drawbacks of each. We show how measurements made in situ reveal patterns of thermal stress that otherwise would be undetectable using more remotely-sensed data. Additionally, we explore the idea that the relevant "grain size" of the physical environment, and thus the spatial scale that must be measured, is a function of (1) the size of the organism relative to local refugia; (2) an organism's ability to sense and to some degree predict near-term environmental conditions; and (3) an animal's movement speed and directionality toward refugia. Similarly, relevant temporal scales depend on the size, behavior, and physiological response of the organism. While miniaturization of dataloggers has significantly improved, several significant limitations still exist, many of which relate to difficulties in recording behavioral responses to changing environmental conditions. We discuss recent innovations in monitoring and modeling intertidal temperatures, and the important role that they have played in bridging ecological and physiological studies of ongoing impacts of climate change.

Spatial Variation in Thermal Stress Experienced by Barnacles on Rocky Shores: The Interplay Between Geographic Variation, Tidal Cycles and Microhabitat Temperatures

“…Biomimetic loggers collecting long-term, high-resolution temperature data can provide a direct measure of temperature variability and extremes experienced by intertidal organisms during periods of high thermal stress such as in the summer/hot season (Helmuth et al, 2006b;Dong et al, 2015;Lathlean et al, 2015;Judge et al, 2018;this study). Based on such temperature data from robobarnacles, our analyses revealed a mosaic pattern of hot (e.g., NE of Taiwan and Thailand) and cool sites or "spots" (e.g., two Hong Kong sites CHK and MB) along locations of the W Pacific and South China Sea, which did not match a simple latitudinal pattern.…”

Mapping microhabitat thermal patterns in artificial breakwaters: Alteration of intertidal biodiversity by higher rock temperature

“…It should be noted that absence of foliose algae or mussels, and reduced cover of barnacles in the mid‐high intertidal zone in the artificial habitat may, themselves also contribute to increased thermal stress (Helmuth et al, ; Lathlean et al, ) as biogenic heterogeneity has an important role providing thermal refuges (Cartwright & Williams, ). However, given we did not explore thermal stress of organisms, which requires a complementary and/or more appropriated temperature‐recording methodology (Judge et al, ), we can only speculate in this context. Notwithstanding, it should be noted that presence/absence of sessile species may also reduce (e.g., microalgae, foliose algal forms) or even increase (e.g., dark crustose algae) the rock temperature recorded, and thus, a negative or positive temperature‐species cover relationship could be expected.…”

“…Ecological engineering solutions to enhance biodiversity and values for ecosystem functioning in artificial infrastructures, should consider the complex spatial‐temporal thermal structure of these novel habitats in their research and planning agendas. Therefore, future studies could consider complementary methodologies to deal with variation of thermal patterns at different spatial scales (e.g., see Judge et al, ; Lathlean & Seuront, for reviews), in a suite of integrated coastal artificial infrastructures. This could shed light on the potential large‐scale effect of coastal urban infrastructures in contributing to exacerbate the local effect on biota of frequent heat waves, and in the subsequent alteration of the coastal climate.…”

“…This method is widely used in a range of fields, especially in intertidal rocky shore systems (Chapperon & Seuront, , ; Lathlean, Ayre, & Minchinton, ; Lathlean & Seuront, ; Rojas et al, ), and allows measurement of the complex thermal patterns of natural and/or artificial surfaces at micro‐scales (few cm's) (Seuront et al, ). We used this technique because we were focused on the spatial patterns of substrate temperature instead of organisms' tissue temperatures, for which data loggers or thermocouples would be more appropriated (see Judge, Choi, & Helmuth, ). Notwithstanding, we use HOBO TidbiT v2 temperature logger installed in each site to complement recording of temperature temporal variability.…”

“…However, given we did not explore thermal stress of organisms, which requires a complementary and/or more appropriated temperature-recording methodology (Judge et al, 2018), we can only speculate in this context. Notwithstanding, it should be noted that presence/absence of sessile species may also reduce (e.g., microalgae, foliose algal forms) or even increase (e.g., dark crustose algae) the rock temperature recorded, and thus, a negative or positive temperature-species cover relationship could be expected.…”