Most studies on coral reefs have focused on shallow reef ( Montastraea cavernosa has a wide depth distribution, and it is one of the most numerous corals at mesophotic depths. Using a range of optical, physiological, and biochemical approaches, the relative dependence on autotrophy vs. heterotrophy was assessed for this coral from 3 to 91 m. These measurements show that the quantum yield of PSII fluorescence increases signific...

Even after decades of investigation using multiple sources of evidence, the natural histories of some species remain unclear (i.e. cryptogenic). A key example is Littorina littorea , the most abundant intertidal snail in northeastern North America. Native to Europe, the snail's ecological history in North America has been debated for over 100 years with no definitive resolution. To resolve its cryptogenic status, we used molec...

We examined the response of four species of New Zealand marine algae ( Ecklonia radiata, Apophlaea lyallii, Rhodymenia spp., Ulva lactuca ) and a sea urchin ( Evechinus chloroticus ) to spatial variation in ultraviolet radiation (UV‐R) by examining the concentration of UV‐R absorbing compounds known as mycosporine‐like amino acids (MAAs). The purpose was to understand how, and the degree to which, local marine species could po...

Stratospheric ozone depletion over Antarctica is expected to continue for the next 50 years, with increases in ecologically damaging ultraviolet radiation (UVR: 290–400 nm), specifically the ultraviolet‐B (UVB: 290–320 nm) portion of the spectrum. Most of coastal Antarctica is covered with 2–3 m of annual sea ice during the occurrence of the “ozone hole.” This physical barrier to UVR transmission has long been assumed to provi...

Fluorescent pigments in several Indo‐Pacific and Caribbean anthozoans have recently been identified as proteins related to the Green‐fluorescent protein (GFP) of the hydromedusa Aequorea victoria . Here we show that GFP is widely distributed in many Caribbean species. The fluorescence excitation and emission spectra for the pigment are similar to those reported elsewhere for coral and noncoral GFP and the fluorescence quantum...

A prototype in‐water laser line‐scanning multispectral fluorescence imaging system was evaluated for its ability to provide data that could be used to determine the quantitative distribution and abundance of various functional groups on coral reefs. The system collected fluorescence imagery in three spectral bands with 1 cm 2 resolution at sites in Florida and the Bahamas. Fluorescence excitation was at 488 nm, and imagery was...

In zooxanthellate corals, excess excitation energy can be dissipated as heat (nonphotochemical quenching), thereby providing protection against oxidative damage by supraoptimal light in shallow reefs. To identify and quantify the photoprotective mechanisms, we studied the diel variability of chlorophyll fluorescence yields and photosynthetic parameters in situ in corals, using moored and SCUBA‐based fast‐repetition‐rate fluoro...

The congeneric species Montastraea faveolata and Montastraea cavernosa are important hermatypic corals on reefs throughout the Bahamas, Caribbean, and the Florida reef tract that have overlapping bathymetric distributions. However, these congeners differ in their respective abundance at similar depths. The underlying mechanism for these patterns may partly be because of their relative dependence on photoautotrophy versus heter...

A direct relationship exists between irradiance of solar ultraviolet (UV) radiation and concentration of UV‐absorbing compounds, know as mycosporine‐like amino acids (MAAs), in the Hawaiian reef coral Pocillopora damicornis. However, MAA concentration is also influenced by flow regime and the irradiance of photosynthetically active radiation (PAR). High irradiances of UV radiation in reef environments are correlated with high...