UV‐absorbing compounds in the coral <i>Pocillopora damicornis</i>: Interactive effects of UV radiation, photosynthetically active radiation, and water flow

Jokiel, Paul L.; Lesser, Michael P.; Ondrusek, Michael

doi:10.4319/lo.1997.42.6.1468

Cited by 56 publications

(34 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Differences in water movement and photosynthetically available radiation (PAR, 400 to 700 nm) across depths also affect the concentration of MAAs (Jokiel et al 1997). In that study, however, concentrations of MAAs did not increase with irradiance in its lower range where there would have been a marked increase in photosynthesis, but increased only at higher levels of PAR where photosynthesis would already have been saturated.…”

Section: Introductioncontrasting

confidence: 40%

“…Shick et al 2000). This is particularly true because fluences of both PAR and UVR are highly correlated (Jokiel et al 1997). As Lesser (2004) noted, there has been no definitive study on the effects of UVR or other environmental factors on the stoichiometry of photosynthetic carbon fixation, the flow of carbon into the shikimic acid pathway, and the accumulation of MAAs.…”

Section: Introductionmentioning

confidence: 99%

“…LaJeunesse (2002) in particular noted the restriction of Clade A zooxanthellae to hosts living in shallow water, where fluences of UVR are high (as, necessarily, is PAR: Jokiel et al 1997, Jokiel 2004, and associated this with the apparently unique ability (among Symbiodinium spp.) of members of this clade to synthesize MAAs.…”

Section: Conclusion and Prospectsmentioning

confidence: 99%

See 2 more Smart Citations

Effects of starvation, ammonium concentration, and photosynthesis on the UV-dependent accumulation of mycosporine-like amino acids (MAAs) in the coral Stylophora pistillata

Ferrier‐Pagés¹,

Grover²,

Allemand³

2005

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

This study addresses several unresolved questions regarding the biosynthesis, metabolism, regulation, and diversity of MAAs in zooxanthellate scleractinian corals. Starved colonies of Stylophora pistillata accumulated the same concentrations of mycosporine-like amino acids (MAAs) as fed corals after 28 d of exposure to photosynthetically available radiation (PAR) and ultraviolet radiation (UVR), suggesting that dietary MAAs are of little quantitative importance in this phototrophic symbiosis. Starved corals continued to accumulate MAAs and conserved them disproportionally compared with declining protein and chlorophyll a, indicating the priority placed on maintaining this UV-sunscreen defense. In 2 different colonies (SP1 and SP2) exposed to enriched (10 µM) ammonium and PAR + UVR during starvation, the final concentrations of MAAs and chlorophyll a were identical. However, under ambient ammonium (< 0.4 µM), SP2 produced MAAs at the expense of chlorophyll a, whereas SP1 maintained chlorophyll a levels but synthesized less MAA. Ammonium consistently affected only the accumulation of primary, Symbiodinium-MAAs (mycosporine glycine, shinorine, porphyra-334, and mycosporine-2 glycine) and not secondary MAAs derived from the former, probably in the host's tissues. Mycosporine-2 glycine and palythine (a secondary MAA) were synthesized by SP1 but not SP2, suggesting (1) genotypic differences between the zooxanthellae in SP1 and SP2, and (2) a biosynthetic relationship between these 2 MAAs that we proposed previously. Exposure to UVR alone did not support large-scale biosynthesis of MAAs in S. pistillata, and accumulation of the full suite of MAAs required PAR + UVR; together with an inhibitory effect of DCMU, this indicates that photosynthesis is required for the UV-stimulated, de novo biosynthesis of MAAs. Cultures of zooxanthellae isolated from S. pistillata and exposed to PAR + UVR showed increased levels of shinorine, and some production of mycosporine-glycine. Host extract had no qualitative effect on the MAAs produced by these zooxanthellae.

show abstract

Section: Introductioncontrasting

confidence: 40%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of starvation, ammonium concentration, and photosynthesis on the UV-dependent accumulation of mycosporine-like amino acids (MAAs) in the coral Stylophora pistillata

Ferrier‐Pagés¹,

Grover²,

Allemand³

2005

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…The UV-absorbing compounds, or MAAs, in M. faveolata and M. cavernosa at 10 m were not signif-icantly different from one another, although significant differences between the two species were observed at 18 m, with M. cavernosa having significantly more total MAAs. Differences between depths were observed and probably reflect the attenuation of UV radiation that contributes to changes in MAA concentration (Dunlap et al 1986;Jokiel et al 1997). The differences between the two species at 18 m could potentially represent a strategy to absorb and utilize as much of the available underwater spectrum of UV and visible radiation as possible.…”

Section: Discussionmentioning

confidence: 99%

Light absorption and utilization by colonies of the congeneric hermatypic corals Montastraea faveolata and Montastraea cavernosa

Lesser

Mazel

Phinney

et al. 2000

Limnology & Oceanography

View full text Add to dashboard Cite

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 heterotrophy. The dependence of these two corals on photoautotrophy was examined quantifying the optical properties and productivity of these two species of corals at two different depths in the Dry Tortugas. Maximum surface irradiances in the Dry Tortugas during this study varied from 1,900 to 2,100 mol quanta m Ϫ2 s Ϫ1. Spectral attenuation coefficients calculated from the 1995 and 1996 irradiance data differed by as little as 10% within the visible wavelengths (photosynthetically active radiation [PAR], 400-700 nm), suggesting year-to-year similarities in the optical properties of the overlying water column. Underwater irradiances of PAR were ϳ400 mol quanta m Ϫ2 s Ϫ1 and 25 mol quanta m Ϫ2 s Ϫ1 at 10 m and 18 m, respectively. Significantly lower rates of maximum photosynthesis were observed for samples of M. cavernosa compared with M. faveolata at 10 m and 18 m. For samples of M. faveolata from both depths, the mean chlorophyll-specific absorption (a*) across all PAR wavelengths was greater than that of M. cavernosa. When spectrally corrected for the underwater light field and used to calculate the minimum quantum requirements (1/ m ) of these corals at each depth, we observed that M. faveolata always had higher 1/ m than M. cavernosa (50 versus 18 quanta O 2 Ϫ1 and 39 versus 15 quanta O 2 Ϫ1 at 10 m and 18 m, respectively). M. cavernosa, with its greater pigment concentrations and lower a*, exhibits a significant package effect that results in a smaller functional optical cross section and lower maximum photosynthetic capacities, whereas M. faveolata at the same depths, despite the greater minimum quantum requirements, has a larger functional optical cross section and enhanced absorption of available visible radiation, resulting in a greater maximum photosynthetic capacity. Based on polyp size, corallite structure, and surface area considerations, M. faveolata appears to depend on photoautotrophy versus heterotrophy to a greater extent than its congener, M. cavernosa. Recent data suggest, however, that polyp size alone may not be a good indicator for differences in trophic strategies and that coordinated studies on feeding and productivity in corals are needed to better understand their ecological distributions.

show abstract

“…Bleaching prevalence and intensity usually increase with water temperature and the duration of the temperature anomaly (Berkelmans 2002, McWilliams et al 2005). However, a wide variety of other environmental factors also appears to influence intraspecific differences in bleaching (Gleason 1993, Jokiel et al 1997, Berkelmans et al 2004, Obura 2005, including exposure to extreme tides and desiccation (Anthony & Kerswell 2007), shading (Mumby et al 2001), wave exposure (Anthony & Kerswell 2007), and history of disturbances impacting individual coral colonies (Kinzie et al 2001, Brown et al 2002, Baker et al 2004, Sotka & Thacker 2005. For example, bleaching declines through serial warming events when coral assemblages and/or their zooxanthellae acquire phenotypic (acclimation) and/or genotypic (adaptation) resistance to thermal stress (Rowan et al 1997, Hoegh-Guldberg 1999, Adjeroud et al 2002.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Reef structure regulates small-scale spatial variation in coral bleaching

Lenihan¹,

Adjeroud²,

Kotchen³

et al. 2008

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Coral bleaching is often characterized by high spatial variation across reef systems. Using a field survey and manipulative experiment, we tested whether the physical structure of coral reefs modifies environmental conditions that, in turn, influence spatial variation in bleaching in 3 scleractinian corals, Pocillopora verrucosa, Acropora elseyi, and Porites rus. Corals inhabit mainly the hard-bottom seafloor, or dead or partially dead coral heads ('bommies'). Bommies (0.10 to 3.0 m tall) position corals at different water depths and expose them to differences in light, temperature, hydrodynamics, and sedimentation, factors that can influence patterns of bleaching. We conducted our study in association with a 14 d warming event that caused bleaching in lagoons of Moorea, French Polynesia. Bleaching in naturally occurring colonies of Pocillopora spp. and Acopora spp. was greater on the seafloor (0 m tall) than on short (0.35 to 0.40 m tall) and tall bommies (1.0 to 1.2 m tall). Bleaching in P. verrucosa and A. elseyi transplanted to reef structures in the experiment generally decreased with increasing reef height (seafloor > short bommies > tall bommies). P. rus did not bleach under any conditions observed. Regression analyses revealed that reef structure controlled current speed and sedimentation at the microhabitat scale (from centimeters to meters), and that these factors regulated bleaching and mortality in P. verrucosa and A. elseyi. Our results imply that the physical structure of shallow water reef habitat influences the performance of coral colonies by modifying environmental stress, and that accounting for this structure is important in managing coral reef systems.KEY WORDS: Bleaching · Coral · Environmental stress · Hydrodynamics · Habitat structure · Light · Sedimentation · Temperature Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 370: [127][128][129][130][131][132][133][134][135][136][137][138][139][140][141] 2008 conditions, thereby reducing environmental stress and regulating coral performance.Decline in coral populations and associated degradation of reef communities are being reported worldwide with increasing frequency (Hughes et al. 2003). Natural catastrophes, including storms, predator outbreaks, and disease, kill corals and damage reefs (Connell et al. 1997, Hughes et al. 2003, as do many anthropogenic disturbances (Hughes 1994, Jackson et al. 2001, Fox & Caldwell 2006. Coral bleaching is both a natural and human-induced phenomenon that causes complex spatial heterogeneity in coral mortality and resulting changes in coral community composition (Lang et al. 1988, Glynn 1996, Brown et al. 2002, Coles & Brown 2003. Corals bleach when they lose symbiotic dinoflagellate algae (zooxanthellae), or when symbionts lose photosynthetic pigment. Without energy from symbiont photosynthesis, primary production is reduced and coral mortality increases (Glynn 1993). Corals bleach in response to many environmental stressors (Brown 1997), but a com...

show abstract

UV‐absorbing compounds in the coral Pocillopora damicornis: Interactive effects of UV radiation, photosynthetically active radiation, and water flow

Cited by 56 publications

References 12 publications

Effects of starvation, ammonium concentration, and photosynthesis on the UV-dependent accumulation of mycosporine-like amino acids (MAAs) in the coral Stylophora pistillata

Effects of starvation, ammonium concentration, and photosynthesis on the UV-dependent accumulation of mycosporine-like amino acids (MAAs) in the coral Stylophora pistillata

Light absorption and utilization by colonies of the congeneric hermatypic corals Montastraea faveolata and Montastraea cavernosa

Reef structure regulates small-scale spatial variation in coral bleaching

Contact Info

Product

Resources

About