Marina Carreiro E Silva - Academia.edu (original) (raw)

Papers by Marina Carreiro E Silva

Understanding the life-cycle of organisms colonizing deep-sea habitats where mining activities mi... more Understanding the life-cycle of organisms colonizing deep-sea habitats where mining activities might take place in the near future remains one of the most critical knowledge gaps that will need to be bridged if we want to be able to mitigate the impacts of resource extraction through the development of spatial management plans for example. The (re)colonization of impacted areas will greatly depends on the connectivity existing between populations, i.e. the ability of new colonists to travel from other areas, settle, grow and reproduce. The objective of this work was to gather all available data concerning reproductive biology and larval dispersal of species inhabiting areas which may be targeted by mining activities as defined in the MIDAS project: The Mid-Atlantic Ridge (MAR), the Clarion-Clipperton Fracture Zone (CCFZ) in the North Pacific, and Arctic gas hydrates. Most data gathered here concerns the MAR, since very few and no data are currently available for the Arctic gas hydrates, and the CCFZ, respectively. Species inhabiting hydrothermal vent sites on the MAR have been relatively well studied compared to species living in the other target areas of the MIDAS project. Nevertheless, reproductive or larval dispersal data are available for less than 15% of the MAR species, and in most case, data are limited to a very low number of biological traits. None of the species inhabiting these sites has had its life-cycle fully characterized. In particular, time-series observations that are required to describe reproductive rhythms are only rarely available. The database highlights the amount of data that is still needed to be able to develop models simulating population connectivity and spatial management plans to mitigate mining impacts.

Marine Pollution Bulletin 64: 602–613, 2012

Marine Ecology Progress Series 458: 103–122, 2012

Deep-Sea Research II , 2013

Marine Ecology Progress Series 473: 189–199 , Jan 2013

Five colonies of black coral Leiopathes sp. were collected as bycatch from depths of 293 to 366 m... more Five colonies of black coral Leiopathes sp. were collected as bycatch from depths of 293 to 366 m from the Condor, Açor, and Voador seamounts (Azores region). The colonies had axial diameters between 4.9 and 33.1 mm and heights between 43 and 175 cm. Their ages and radial growth rates were estimated using radiocarbon dating. Results indicated that the smallest and largest colonies had similar radial growth rates of 5 to 7 µm yr −1 , whereas the other 3 colonies had grown more rapidly by a factor of 3 to 5 at ~20 to 30 µm yr −1 . Colony lifespan ranged between 265 ± 90 and 2320 ± 90 yr. Fine-scale sampling along a radial transect from the edge to the center of the 2320 yr old Leiopathes sp. revealed variable growth rates throughout the colony lifespan. Slower radial growth rates of ~4 to 5 µm yr −1 were recorded over the initial 1600 yr and the last 300 yr of its life span, and a period of more rapid growth (20 µm yr −1 ) over the intermediate 400 yr of its life. Variability in radial growth rates among colonies resulted in colony ages that were not linearly correlated to colony axis diameter or height. Our findings of great longevity and slow growth rates for Leiopathes sp. agree with other Leiopathes sp. age and growth studies, indicating that colony and population recovery from damage or removal may take centuries to millennia.

Marine Ecology-progress Series, 2009

Closed cages were used in Glovers Atoll, Belize to test the effects of organic matter (OM) and in... more Closed cages were used in Glovers Atoll, Belize to test the effects of organic matter (OM) and inorganic nutrient (N + P) additions on microbial euendolithic communities (bacteria, fungi, and algae) and their rates of bioerosion of Strombus gigas shells during a 49 d fertilization experiment. We hypothesized that the addition of OM would release heterotrophic microborers from C-limitation and at the same time reduce light levels for euendolithic microalgae, thus changing the microborers' community composition and their bioerosion rates. The addition of OM increased the abundance of heterotrophs (particularly fungi), but only when OM was added alone, not when it was combined with inorganic nutrients. In contrast, both cyanobacteria and green algae were stimulated by the addition of inorganic nutrients, but were not affected by OM; these taxa were 4 times more abundant in treatments with inorganic nutrients than in control and OM treatments. Green algae dominated the control, N + P and N + P + OM treatments (77 to 87% green algae, 6 to 8% cyanobacteria, 4 to 16% heterotrophs), whereas in the OM treatment, heterotrophs represented nearly 50% of the total area colonized (52% green algae, 4% cyanobacteria, 44% heterotrophs). Bioerosion rates in treatments with added inorganic nutrients (396 g CaCO 3 m -2 yr -1 in the N + P treatment and 370 g CaCO 3 m -2 yr -1 in the N + P + OM treatment) were 9-fold greater than bioerosion rates in the control and OM treatments (43 and 48 g CaCO 3 m -2 yr -1 , respectively), and were not affected by OM addition. We conclude that inorganic nutrients are a major factor controlling the microbioerosion rates and the abundance of euendolithis algae over fungi in carbonate substrata. Microborers act in synergy with the grazers that feed on them and with macroborers that increase the internal surfaces available for microborers to colonize. As a result, increased nutrients can initiate a feedback loop where bioerosion processes reinforce one another, leading to accelerated erosion of the reef framework.

Marine Pollution Bulletin, 2007

Nitrogen and phosphorous fertilizers were used to determine their short-term summer effects on al... more Nitrogen and phosphorous fertilizers were used to determine their short-term summer effects on algal colonization, abundance, and species composition in moderate herbivory treatments. Secondary succession of algae on coral skeletons was examined in four treatments: an untreated control, a pure phosphate fertilizer, a pure nitrogen fertilizer, and an equal mix of the two fertilizers. Turf algae cover was the only measure of algae abundance to respond significantly to fertilization. Turf cover was three times higher in treatments with added nitrogen when compared with the pure phosphorus treatment. These turfs were dominated by green and cyanobacteria taxa, namely Enteromorpha prolifera, Lyngbya confervoides, and two species of Cladophora. The phosphate treatment was dominated by encrusting corallines and the cyanobacteria L. confervoides, while the controls had the highest cover of frondose brown algae, namely Padina sanctae-crucis and two species of Dictyota. Results indicate that turf algae were co-limited by nitrogen and phosphorus but enrichment appeared to inhibit brown frondose algae that currently dominate these reefs. Number of species was lowest on the pure phosphorus and nitrogen treatments, highest in the controls and intermediate in the mixed treatments, which suggests that diversity is reduced most by an imbalanced nutrient ratio.

Ices Journal of Marine Science, 2010

In the Azores, Northeast Atlantic, an undescribed epizoan zoanthid is often found in association ... more In the Azores, Northeast Atlantic, an undescribed epizoan zoanthid is often found in association with the cold-water gorgonian Callogorgia verticillata at 110 – 800 m depth. This zoanthid was identified as a new species, Isozoanthus primnoidus sp. nov., based on morphological and anatomical characters of the polyps and type of cnidae. The distinguishing features of I. primnoidus are coe-nenchyme, column, and oral disc light brown, with short, translucent tentacles. Contracted polyps have column diameter up to 3 mm and height up to 2 mm. Ectoderm and outer mesogloea are densely encrusted with mineral particles and gorgonian sclerites. Capitulum bears a maximum of 14 distinctive ridges. Isozoanthus primnoidus was associated with 17% of C. verticillata colonies studied, and covered 14 + 5% of the gorgonian colony. There was strong evidence of a parasitic relationship whereby I. primoidus progressively eliminates gorgonian tissue and uses the gorgonian axis for structure and support, and sclerites for protection.

Ices Journal of Marine Science, 2010

The Azores region harbours the richest communities of stylasterid corals in the Northeast Atlanti... more The Azores region harbours the richest communities of stylasterid corals in the Northeast Atlantic area. Of the nine deep-water species found there, Errina dabneyi seems to be the most abundant species; it is commonly collected as bycatch from longline fishing. E. dabneyi host Pedicularia gastropods on their branches, and a detailed study of shell shape and morphometry at different growth stages, complemented by shell characterization through scanning electron microscopy, allows the individuals to be identified as Pedicularia sicula. The incidence of this species on E. dabneyi was high (69.8%), with abundances ranging between 1 and 223 individuals per colony. The pediculariids exhibited a high degree of plasticity and produced evident traces on the stylasterid skeletons at their fixation points, suggesting that they are ectoparasites and not predators of E. dabneyi. The stylasterid colonies also hosted a rich associated fauna dominated by suspension-feeders using the coral as substratum and for protection.

Marine Biodiversity

Observations of deep-sea homolids are becoming more common, but good-resolution imagery of these ... more Observations of deep-sea homolids are becoming more common, but good-resolution imagery of these crabs in the natural environment is still scarce. Sixteen new in situ observations of Paromola cuvieri from various locations within the central and eastern groups of the Azores Archipelago (Northeast Atlantic) are described here based on video footage collected by two submersible vehicles. Crabs were found on coral gardens and deep-sea sponge aggregations, which are priority habitats of conservation importance under OSPARCOM. Diverse sessile megafauna were recorded (>59 taxa), including sponges, hydroids, corals, brachiopods, crinoids and oysters. Overall, 75% of the crabs were carrying live specimens of sessile invertebrates, mainly sponges and cold-water corals. Object selection shows to be a more complex process than previously thought, in which factors such as morphology, size and weight of objects and also palatability seem to be more important in the process of object selection than their availability.

Coral Reefs, 2005

The effect of herbivore abundance and nutrients on microborer communities and their rates of bioe... more The effect of herbivore abundance and nutrients on microborer communities and their rates of bioerosion of Strombus gigas shells was studied using herbivore-exclusion cages and inorganic fertilizers at Glovers Reef, Belize. Microborers colonizing shells in each treatment were identified and their colonization rates were calculated from scanning electron microscopy of the boring casts. In all treatments the dominant microborer was the green alga Phaeophila sp. Cyanobacteria were most abundant within fertilized and fungi in unfertilized treatments. The highest microbioerosion rates and most distinctive microborer community were found on the treatment with both reduced herbivores and fertilization. All fertilized treatments had significantly higher bioerosion rates than unfertilized treatments. Treatments with macrograzer access had microbioerosion rates less than half the fertilized cages. Bioerosion rates in unfertilized treatments were lowest and not different with and without macrograzers. Consequently, increased nutrient concentrations on reefs have the potential to increase rates of microbioerosion and macrograzers can modify the composition and density of the microborer community.

Journal of Experimental Marine Biology and Ecology, 2001

During feeding, echinoids remove a large proportion of calcium carbonate in addition to the algae... more During feeding, echinoids remove a large proportion of calcium carbonate in addition to the algae growing on dead coral and are consequently of importance in estimating the turnover of organic and inorganic carbon in coral reefs. Rates of herbivory and the erosion of dead coral substratum, referred to as bioerosion, by the most abundant echinoid species in Kenyan reefs, Echinothrix diadema (Linnaeus), Diadema setosum (Leske), D. savignyi (Michelin) and Echinometra mathaei (de Blainville), were compared in three different reef categories with different histories of fishing and its exclusion. These were reefs: (i) protected within Marine National Parks, which exclude all forms of fishing, coral and shell collection for more than 25 years; (ii) one reef within a Marine Park, which has received protection from fishing activities for 8 years (referred to as ‘newly protected’ reef); and (iii) unprotected reefs, which experience heavy fishing and some coral collection. The aim was to investigate the grazing and bioerosion activity by the above echinoid species in these reef categories. We surveyed sea urchin population densities and determined their rates of bioerosion and herbivory per individual and square meter. Individual rates of bioerosion and herbivory, of the species D. setosum, D. savignyi and E. diadema were estimated from laboratory gut content analysis and gut evacuation experiments in the field, using elevated underwater cages. Individual rates of bioerosion and herbivory of E. mathaei were obtained from a previous field study [J. Exp. Mar. Biol. Ecol. 147 (1991) 121]. Sea urchin bioerosion was greater than herbivory for all studied species and proportional to the body size of the sea urchin species. The large-bodied E. diadema exhibited the highest bioerosion and herbivory rates (5.5±0.9 and 2.2±0.3 g individual−1 day−1, respectively) followed by D. setosum (1.8±0.3 and 1.1±0.2 g individual−1 day−1) and D. savignyi (0.7±0.2 and 0.4±0.1 g individual−1 day−1). Highest sea urchin densities were recorded at unprotected reefs (6.2±1.5 individual m−2), and therefore, bioerosion and herbivory by sea urchins were also highest in this reef category (1180±230 g CaCO3 m−2 year−1 and 450±77 g algae m−2 year−1). Protected reefs recorded 20 times lower sea urchin bioerosion and herbivory rates (50.3±25.8 g CaCO3 m−2 year−1 and 20.7±10.4 g algae m−2 year−1), due to the low sea urchin population densities in these reefs (0.06±0.01 individual m−2). The newly protected reef, with intermediate number of sea urchins (1.2±0.1 individual m−2), had intermediate rates of sea urchin bioerosion and herbivory (711±157 g CaCO3 m−2 year−1 and 299±63 g algae m−2 year−1). These findings suggest that echinoids are important in the carbon cycle and reef development, and that fishing can influence these ecological processes.

Understanding the life-cycle of organisms colonizing deep-sea habitats where mining activities mi... more Understanding the life-cycle of organisms colonizing deep-sea habitats where mining activities might take place in the near future remains one of the most critical knowledge gaps that will need to be bridged if we want to be able to mitigate the impacts of resource extraction through the development of spatial management plans for example. The (re)colonization of impacted areas will greatly depends on the connectivity existing between populations, i.e. the ability of new colonists to travel from other areas, settle, grow and reproduce. The objective of this work was to gather all available data concerning reproductive biology and larval dispersal of species inhabiting areas which may be targeted by mining activities as defined in the MIDAS project: The Mid-Atlantic Ridge (MAR), the Clarion-Clipperton Fracture Zone (CCFZ) in the North Pacific, and Arctic gas hydrates. Most data gathered here concerns the MAR, since very few and no data are currently available for the Arctic gas hydrates, and the CCFZ, respectively. Species inhabiting hydrothermal vent sites on the MAR have been relatively well studied compared to species living in the other target areas of the MIDAS project. Nevertheless, reproductive or larval dispersal data are available for less than 15% of the MAR species, and in most case, data are limited to a very low number of biological traits. None of the species inhabiting these sites has had its life-cycle fully characterized. In particular, time-series observations that are required to describe reproductive rhythms are only rarely available. The database highlights the amount of data that is still needed to be able to develop models simulating population connectivity and spatial management plans to mitigate mining impacts.

Marine Pollution Bulletin 64: 602–613, 2012

Marine Ecology Progress Series 458: 103–122, 2012

Deep-Sea Research II , 2013

Marine Ecology Progress Series 473: 189–199 , Jan 2013

Five colonies of black coral Leiopathes sp. were collected as bycatch from depths of 293 to 366 m... more Five colonies of black coral Leiopathes sp. were collected as bycatch from depths of 293 to 366 m from the Condor, Açor, and Voador seamounts (Azores region). The colonies had axial diameters between 4.9 and 33.1 mm and heights between 43 and 175 cm. Their ages and radial growth rates were estimated using radiocarbon dating. Results indicated that the smallest and largest colonies had similar radial growth rates of 5 to 7 µm yr −1 , whereas the other 3 colonies had grown more rapidly by a factor of 3 to 5 at ~20 to 30 µm yr −1 . Colony lifespan ranged between 265 ± 90 and 2320 ± 90 yr. Fine-scale sampling along a radial transect from the edge to the center of the 2320 yr old Leiopathes sp. revealed variable growth rates throughout the colony lifespan. Slower radial growth rates of ~4 to 5 µm yr −1 were recorded over the initial 1600 yr and the last 300 yr of its life span, and a period of more rapid growth (20 µm yr −1 ) over the intermediate 400 yr of its life. Variability in radial growth rates among colonies resulted in colony ages that were not linearly correlated to colony axis diameter or height. Our findings of great longevity and slow growth rates for Leiopathes sp. agree with other Leiopathes sp. age and growth studies, indicating that colony and population recovery from damage or removal may take centuries to millennia.

Marine Ecology-progress Series, 2009

Closed cages were used in Glovers Atoll, Belize to test the effects of organic matter (OM) and in... more Closed cages were used in Glovers Atoll, Belize to test the effects of organic matter (OM) and inorganic nutrient (N + P) additions on microbial euendolithic communities (bacteria, fungi, and algae) and their rates of bioerosion of Strombus gigas shells during a 49 d fertilization experiment. We hypothesized that the addition of OM would release heterotrophic microborers from C-limitation and at the same time reduce light levels for euendolithic microalgae, thus changing the microborers' community composition and their bioerosion rates. The addition of OM increased the abundance of heterotrophs (particularly fungi), but only when OM was added alone, not when it was combined with inorganic nutrients. In contrast, both cyanobacteria and green algae were stimulated by the addition of inorganic nutrients, but were not affected by OM; these taxa were 4 times more abundant in treatments with inorganic nutrients than in control and OM treatments. Green algae dominated the control, N + P and N + P + OM treatments (77 to 87% green algae, 6 to 8% cyanobacteria, 4 to 16% heterotrophs), whereas in the OM treatment, heterotrophs represented nearly 50% of the total area colonized (52% green algae, 4% cyanobacteria, 44% heterotrophs). Bioerosion rates in treatments with added inorganic nutrients (396 g CaCO 3 m -2 yr -1 in the N + P treatment and 370 g CaCO 3 m -2 yr -1 in the N + P + OM treatment) were 9-fold greater than bioerosion rates in the control and OM treatments (43 and 48 g CaCO 3 m -2 yr -1 , respectively), and were not affected by OM addition. We conclude that inorganic nutrients are a major factor controlling the microbioerosion rates and the abundance of euendolithis algae over fungi in carbonate substrata. Microborers act in synergy with the grazers that feed on them and with macroborers that increase the internal surfaces available for microborers to colonize. As a result, increased nutrients can initiate a feedback loop where bioerosion processes reinforce one another, leading to accelerated erosion of the reef framework.

Marine Pollution Bulletin, 2007

Nitrogen and phosphorous fertilizers were used to determine their short-term summer effects on al... more Nitrogen and phosphorous fertilizers were used to determine their short-term summer effects on algal colonization, abundance, and species composition in moderate herbivory treatments. Secondary succession of algae on coral skeletons was examined in four treatments: an untreated control, a pure phosphate fertilizer, a pure nitrogen fertilizer, and an equal mix of the two fertilizers. Turf algae cover was the only measure of algae abundance to respond significantly to fertilization. Turf cover was three times higher in treatments with added nitrogen when compared with the pure phosphorus treatment. These turfs were dominated by green and cyanobacteria taxa, namely Enteromorpha prolifera, Lyngbya confervoides, and two species of Cladophora. The phosphate treatment was dominated by encrusting corallines and the cyanobacteria L. confervoides, while the controls had the highest cover of frondose brown algae, namely Padina sanctae-crucis and two species of Dictyota. Results indicate that turf algae were co-limited by nitrogen and phosphorus but enrichment appeared to inhibit brown frondose algae that currently dominate these reefs. Number of species was lowest on the pure phosphorus and nitrogen treatments, highest in the controls and intermediate in the mixed treatments, which suggests that diversity is reduced most by an imbalanced nutrient ratio.

Ices Journal of Marine Science, 2010

In the Azores, Northeast Atlantic, an undescribed epizoan zoanthid is often found in association ... more In the Azores, Northeast Atlantic, an undescribed epizoan zoanthid is often found in association with the cold-water gorgonian Callogorgia verticillata at 110 – 800 m depth. This zoanthid was identified as a new species, Isozoanthus primnoidus sp. nov., based on morphological and anatomical characters of the polyps and type of cnidae. The distinguishing features of I. primnoidus are coe-nenchyme, column, and oral disc light brown, with short, translucent tentacles. Contracted polyps have column diameter up to 3 mm and height up to 2 mm. Ectoderm and outer mesogloea are densely encrusted with mineral particles and gorgonian sclerites. Capitulum bears a maximum of 14 distinctive ridges. Isozoanthus primnoidus was associated with 17% of C. verticillata colonies studied, and covered 14 + 5% of the gorgonian colony. There was strong evidence of a parasitic relationship whereby I. primoidus progressively eliminates gorgonian tissue and uses the gorgonian axis for structure and support, and sclerites for protection.

Ices Journal of Marine Science, 2010

The Azores region harbours the richest communities of stylasterid corals in the Northeast Atlanti... more The Azores region harbours the richest communities of stylasterid corals in the Northeast Atlantic area. Of the nine deep-water species found there, Errina dabneyi seems to be the most abundant species; it is commonly collected as bycatch from longline fishing. E. dabneyi host Pedicularia gastropods on their branches, and a detailed study of shell shape and morphometry at different growth stages, complemented by shell characterization through scanning electron microscopy, allows the individuals to be identified as Pedicularia sicula. The incidence of this species on E. dabneyi was high (69.8%), with abundances ranging between 1 and 223 individuals per colony. The pediculariids exhibited a high degree of plasticity and produced evident traces on the stylasterid skeletons at their fixation points, suggesting that they are ectoparasites and not predators of E. dabneyi. The stylasterid colonies also hosted a rich associated fauna dominated by suspension-feeders using the coral as substratum and for protection.

Marine Biodiversity

Observations of deep-sea homolids are becoming more common, but good-resolution imagery of these ... more Observations of deep-sea homolids are becoming more common, but good-resolution imagery of these crabs in the natural environment is still scarce. Sixteen new in situ observations of Paromola cuvieri from various locations within the central and eastern groups of the Azores Archipelago (Northeast Atlantic) are described here based on video footage collected by two submersible vehicles. Crabs were found on coral gardens and deep-sea sponge aggregations, which are priority habitats of conservation importance under OSPARCOM. Diverse sessile megafauna were recorded (>59 taxa), including sponges, hydroids, corals, brachiopods, crinoids and oysters. Overall, 75% of the crabs were carrying live specimens of sessile invertebrates, mainly sponges and cold-water corals. Object selection shows to be a more complex process than previously thought, in which factors such as morphology, size and weight of objects and also palatability seem to be more important in the process of object selection than their availability.

Coral Reefs, 2005

The effect of herbivore abundance and nutrients on microborer communities and their rates of bioe... more The effect of herbivore abundance and nutrients on microborer communities and their rates of bioerosion of Strombus gigas shells was studied using herbivore-exclusion cages and inorganic fertilizers at Glovers Reef, Belize. Microborers colonizing shells in each treatment were identified and their colonization rates were calculated from scanning electron microscopy of the boring casts. In all treatments the dominant microborer was the green alga Phaeophila sp. Cyanobacteria were most abundant within fertilized and fungi in unfertilized treatments. The highest microbioerosion rates and most distinctive microborer community were found on the treatment with both reduced herbivores and fertilization. All fertilized treatments had significantly higher bioerosion rates than unfertilized treatments. Treatments with macrograzer access had microbioerosion rates less than half the fertilized cages. Bioerosion rates in unfertilized treatments were lowest and not different with and without macrograzers. Consequently, increased nutrient concentrations on reefs have the potential to increase rates of microbioerosion and macrograzers can modify the composition and density of the microborer community.

Journal of Experimental Marine Biology and Ecology, 2001

During feeding, echinoids remove a large proportion of calcium carbonate in addition to the algae... more During feeding, echinoids remove a large proportion of calcium carbonate in addition to the algae growing on dead coral and are consequently of importance in estimating the turnover of organic and inorganic carbon in coral reefs. Rates of herbivory and the erosion of dead coral substratum, referred to as bioerosion, by the most abundant echinoid species in Kenyan reefs, Echinothrix diadema (Linnaeus), Diadema setosum (Leske), D. savignyi (Michelin) and Echinometra mathaei (de Blainville), were compared in three different reef categories with different histories of fishing and its exclusion. These were reefs: (i) protected within Marine National Parks, which exclude all forms of fishing, coral and shell collection for more than 25 years; (ii) one reef within a Marine Park, which has received protection from fishing activities for 8 years (referred to as ‘newly protected’ reef); and (iii) unprotected reefs, which experience heavy fishing and some coral collection. The aim was to investigate the grazing and bioerosion activity by the above echinoid species in these reef categories. We surveyed sea urchin population densities and determined their rates of bioerosion and herbivory per individual and square meter. Individual rates of bioerosion and herbivory, of the species D. setosum, D. savignyi and E. diadema were estimated from laboratory gut content analysis and gut evacuation experiments in the field, using elevated underwater cages. Individual rates of bioerosion and herbivory of E. mathaei were obtained from a previous field study [J. Exp. Mar. Biol. Ecol. 147 (1991) 121]. Sea urchin bioerosion was greater than herbivory for all studied species and proportional to the body size of the sea urchin species. The large-bodied E. diadema exhibited the highest bioerosion and herbivory rates (5.5±0.9 and 2.2±0.3 g individual−1 day−1, respectively) followed by D. setosum (1.8±0.3 and 1.1±0.2 g individual−1 day−1) and D. savignyi (0.7±0.2 and 0.4±0.1 g individual−1 day−1). Highest sea urchin densities were recorded at unprotected reefs (6.2±1.5 individual m−2), and therefore, bioerosion and herbivory by sea urchins were also highest in this reef category (1180±230 g CaCO3 m−2 year−1 and 450±77 g algae m−2 year−1). Protected reefs recorded 20 times lower sea urchin bioerosion and herbivory rates (50.3±25.8 g CaCO3 m−2 year−1 and 20.7±10.4 g algae m−2 year−1), due to the low sea urchin population densities in these reefs (0.06±0.01 individual m−2). The newly protected reef, with intermediate number of sea urchins (1.2±0.1 individual m−2), had intermediate rates of sea urchin bioerosion and herbivory (711±157 g CaCO3 m−2 year−1 and 299±63 g algae m−2 year−1). These findings suggest that echinoids are important in the carbon cycle and reef development, and that fishing can influence these ecological processes.