Parrotfish

Animals often occupy home ranges where they conduct daily activities. In many parrotfishes, large terminal phase (TP) males defend their diurnal (i.e., daytime) home ranges as intraspecific territories occupied by harems of initial phase (IP) females. However, we know relatively little about the exclusivity and spatial stability of these territories. We investigated diurnal home range behavior in several TPs and IPs of five common Caribbean parrotfish species on the fringing coral reefs of Bonaire, Caribbean Netherlands. We computed parrotfish home ranges to investigate differences in space use and then quantified spatial overlap of home ranges between spatially co-occurring TPs to investigate exclusivity. We also quantified the spatial overlap of home ranges estimated from repeat tracks of a few TPs to investigate their spatial stability. We then discussed these results in the context of parrotfish social behavior. Home range sizes differed significantly among species. Spatial overlap between home ranges was lower for intraspecific than interspecific pairs of TPs. Focal TPs frequently engaged in agonistic interactions with intraspecific parrotfish and interacted longest with intraspecific TP parrotfish. This behavior suggests that exclusionary agonistic interactions may contribute to the observed patterns of low spatial overlap between home ranges. The spatial overlap of home ranges estimated from repeated tracks of several TPs of three study species was high, suggesting that home ranges were spatially stable for at least 1 month. Taken together, our results provide strong evidence that daytime parrotfish space use is constrained within fixed intraspecific territories in which territory holders have nearly exclusive access to resources. Grazing by parrotfishes maintains benthic reef substrates in early successional states that are conducive to coral larval settlement and recruitment. Behavioral constraints on parrotfish space use may drive spatial heterogeneity in grazing pressure and affect local patterns of benthic community assembly. A thorough understanding of the spatial ecology of parrotfishes is, therefore, necessary to elucidate their functional roles on coral reefs.

Parrotfishes can often be observed consuming fish feces on coral reefs. Our recent study highlights the nutritional value of these feces to parrotfishes. Four of the five most common species at our study sites (Bonaire, Caribbean Netherlands) consumed feces, mostly from Chromis multilineata. Despite being infrequent (<4% total bites), we estimate that coprophagy may contribute ~27% of the carbon obtained by parrotfishes while foraging on preferred benthic substrates. Chromis feces also have higher protein and lipid contents and lower C:N:P ratios than other foraging targets (algae and cyanobacteria). Coprophagy is, therefore, likely an important and understudied component of parrotfish nutrition.

Parrotfishes are widely considered to be important grazers on coral reefs that remove autotrophic biomass from the reef substrate and create bare space that is conducive to larval coral settlement and recruitment (Bonaldo et al., 2014). Another aspect of parrotfish foraging and trophic ecology that has received very little attention is coprophagy. Coprophagy, the consumption of fecal matter, occurs in many animal taxa and may be an important means of subsidizing nutritional requirements (i.e., micro- and macronutrients) not met through foraging on preferred resources alone (Bailey & Robertson, 1982; Johannes & Satomi, 1966; Negro et al., 2002; Robertson, 1982).

The feces of planktivorous fishes, including Chromis spp., have been identified as important sources of nutrients and trace elements to tropical and temperate reef ecosystems (Geesey et al., 1984; Hamner et al., 1988; Pinnegar & Polunin, 2006). Their feces are readily consumed by a variety of fishes, including parrotfishes (Pinnegar & Polunin, 2006; Robertson, 1982). Although parrotfish coprophagy has been observed in prior studies (Motta & Overholtzer, 1999; Robertson, 1982), its frequency has not yet been quantified.

In May–July 2019, we conducted video-recorded foraging observations of 162 parrotfishes across five fringing coral reef sites in Bonaire, NL to quantify benthic foraging targets for the five most common species on those reefs

With the in-water monitoring activities, STCB collects data on the following CITES species:

• (a) green turtles; (b) hawksbill turtles; (c) loggerhead turtles; (d) sharks; (e) rays.

In addition, data is collected on:

• (f) barracudas; (g) tarpons; (h) rainbow parrotfish; (i) midnight parrotfish; (j) fish schools (creole fish, creole wrasse, black durgon, blue tang/surgeon fish, palometa, chub, bar jack, black margate, horse-eye jack, school master, yellow-tail snapper).
• Time of survey: date and time.
• Environment: horizontal and vertical visibility, food availability, substrate, water temperature.
• Disturbance: presence and number of fishing boats and humans in the survey regions.
• Observers: number of observers and their level of experience.

For the in-water monitoring activities, STCB has divided Bonaire into three survey regions: Northwest Bonaire, Southwest Bonaire and Klein Bonaire. Within these survey regions, eighteen fixed systematically random transects (survey areas) have been set up. Subsequently, an additional eighteen random transects were set up in the areas between the fixed transects. Therefore, a total of 36 transects have been set.

Dutch, Papiamentu and Papiamento below

Parrotfish are more than just a pretty face. The average parrotfish spends up to 90% of its day cleaning the coral reefs. Their sharp beaks allow them to easily scrape algae off corals and rocks, essential for keeping the reefs healthy and thriving. They are especially important to reef health now given the increase in major stressors such as coral bleaching events and Stony Coral Tissue Loss Disease (SCTLD). Increased protection in the Caribbean region will be considered in the next Conference of parties for the Cartagena Convention (COPS) meeting later this year on Aruba. 

(Princess Parrotfish (Scarus taeniopterus). Photo credit: Marion Haarsma)

Coral reefs provide valuable habitat for fish and other animals. People also benefit from the many ecosystem services coral reefs provide including coastal protection, food and income from tourism and fisheries. In fact, coral reefs are one of the most important sources of income for the Dutch Caribbean islands.  

 

Important grazers 

(Photo credit: Marion Haarsma)

Herbivores like parrotfish play a critical role in maintaining healthy coral reefs. They help sustain the delicate balance within the reef by grazing on (macro)algae, which are the main competitors for corals for space and light. The average parrotfish spends up to 90% of its day cleaning the reef. Not only does this fish species keep the algae in check, but these herbivores also create new space for baby corals to attach and grow.  

Besides removing macroalgae and promoting coral settlement and growth, parrotfish are also natural bioeroders producing sediment by grazing on rocks, calcareous algae and corals (less than 10% of their food). Hereby they help recycle nutrients and produce “sand” for (eroded) coastal areas.  

The Global Coral Reef Monitoring Network (GCRMN) report entitled “Status and Trends of Caribbean Coral Reefs: 1970-2012″ by Jackson et al. (2014) documented quantitative trends on coral reef health over 43 years in the wider Caribbean. The report identifies that one of the major drivers of coral reef decline in the Caribbean is the overfishing of herbivores, particularly parrotfish. 

 

Threats 

(Parrotfish on Bonaire’s reef. Photo credit: Steph Wear)

Parrotfish thrive best in healthy coral reefs ecosystems. Therefore, these fish are subjected to the same threats as corals. This includes the negative effects of climate change, ocean acidification, pollution and diseases such as the Stony coral tissue loss disease (SCTLD). In addition, overfishing can quickly wipe out local parrotfish populations. Studies show that reefs are healthier and have a higher recovery resilience capability in locations where parrotfish are protected. This highlights the importance of parrotfish for reefs to be able recover and regrow from these threats. 

 

Protecting Parrotfish 

In the Dutch Caribbean- on Aruba and Bonaire- there are local rules and regulations to protect all parrotfish. On these islands it is prohibited to catch, kill, wound, or disturb them. Luckily for the other islands in the (Dutch) Caribbean, the Kingdom of Netherlands, along with the Republic of France, have formally submitted a proposal to include all parrotfish in Annex III of the Specially Protected Areas and Wildlife (SPAW) Protocol, a regional agreement for the protection and sustainable use of coastal and marine biodiversity in the Wider Caribbean Region. If approved during the next Conference of parties for the Cartagena Convention (COPS) later this year on Aruba, this measure provides a legal framework for the conservation of the parrotfish to ensure and maintain population at an optimal level in the Wider Caribbean. 

Want to learn more about local parrotfish populations? Check out the following related articles: 

Fish poop: an underappreciated food source for coral reef fishes?, 

Recovery of Orbicella annularis corals from parrotfish predation, 

Parrotfish key to reef survival,

https://www.gefcrew.org/carrcu/SPAWSTAC10/SPAW_STAC10_WG.43-INF.17_EN_Parrotfish_Inclusion.pdf\ 

 

DCNA  

The Dutch Caribbean Nature Alliance (DCNA) supports science communication and outreach in the Dutch Caribbean region by making nature related scientific information more widely available through amongst others the Dutch Caribbean Biodiversity Database, DCNA’s news platform BioNews and the press. This article contains the results from several scientific studies but the studies themselves are not DCNA studies. No rights can be derived from the content. DCNA is not liable for the content and the in(direct) impacts resulting from publishing this article. 

 

 

 

 

Papegaaivissen zijn meer dan alleen een mooi gezicht. De gemiddelde papegaaivis besteedt tot 90% van zijn dag aan het schoonmaken van de koraalriffen. Met hun scherpe bek kunnen ze gemakkelijk algen van koralen en rotsen schrapen, essentieel om de riffen gezond te houden. Vooral nu met grote stressfactoren zoals koraalverbleking en Stoney Coral Tissue Loss Disease (SCTLD), zijn ze belangrijk om koraalriffen te helpen herstellen en opnieuw te laten groeien. Verhoogde bescherming in het Caribisch gebied zal worden overwogen tijdens de volgende Conference of parties for the Cartagena Convention (COPS) die later dit jaar op Aruba plaatsvindt.

(Prinses Papegaaivis (Scarus taeniopterus). Photo credit: Marion Haarsma)

Koraalriffen vormen een waardevol leefgebied voor vissen en andere dieren. Mensen profiteren ook van de vele ecosysteemdiensten die koraalriffen bieden, waaronder kustbescherming, voedsel en inkomsten uit toerisme en visserij. Koraalriffen zijn zelfs een van de belangrijkste bronnen van inkomsten voor de Nederlands Caribische eilanden.

 

Belangrijke grazers

(Foto: Marion Haarsma)

Herbivoren zoals papegaaivissen spelen een cruciale rol bij het behoud van gezonde koraalriffen. Ze helpen het delicate evenwicht binnen het rif in stand te houden door te grazen op (macro)algen, die de belangrijkste concurrenten zijn voor koralen om ruimte en licht. De gemiddelde papegaaivis besteedt tot 90% van zijn dag aan het schoonmaken van het rif. Deze vissoort houdt niet alleen de algen onder controle, maar deze herbivoren creëren ook nieuwe ruimte voor babykoralen om zich te hechten en te groeien.

Naast het verwijderen van macroalgen en het bevorderen van de vestiging en groei van koralen, zijn papegaaivissen ook natuurlijke bioeroders die sediment produceren door te grazen op rotsen, kalkalgen en koralen (minder dan 10% van hun voedsel). Hiermee helpen ze bij het recyclen van nutriënten en het produceren van “zand” voor (geërodeerde) kustgebieden.

Het rapport van het Global Coral Reef Monitoring Network (GCRMN) getiteld “Status and Trends of Caribbean Coral Reefs: 1970-2012” door Jackson et al. (2014) documenteerde kwantitatieve trends over de gezondheid van koraalriffen gedurende 43 jaar in het bredere Caribisch gebied. Het rapport identificeert dat een van de belangrijkste oorzaken van de achteruitgang van koraalriffen in het Caribisch gebied de overbevissing van herbivoren, met name papegaaivissen, is.

 

Gevaren

(Papegaaivissen op Bonaire. Foto: Steph Wear)

Papegaaivissen gedijen het best in gezonde ecosystemen van koraalriffen. Daarom worden deze vissen blootgesteld aan dezelfde bedreigingen als koralen. Denk hierbij aan de negatieve effecten van klimaatverandering, verzuring van de oceaan, vervuiling en ziektes zoals de Stoney Coral Tissue Loss Disease (SCTLD). Bovendien kan overbevissing lokale papegaaivispopulaties snel uitroeien. Studies tonen aan dat riffen gezonder zijn en een hoger herstelvermogen hebben op locaties waar papegaaivissen worden beschermd. Dit benadrukt het belang van papegaaivissen voor riffen om te kunnen herstellen en teruggroeien van deze bedreigingen.

 

Papegaaivissen beschermen

In de Nederlandse Cariben – op Aruba en Bonaire – zijn er lokale regels en voorschriften om alle papegaaivissen te beschermen. Op deze eilanden is het verboden ze te vangen, te doden, te verwonden of te storen. Gelukkig voor de andere eilanden in de (Nederlandse) Cariben heeft het Koninkrijk der Nederlanden, samen met de Republiek Frankrijk, formeel een voorstel ingediend om alle papegaaivissen op te nemen in bijlage III van het Specially Protected Areas and Wildlife (SPAW) Protocol, een regionaal overeenkomst voor de bescherming en het duurzame gebruik van de kust- en mariene biodiversiteit in de ruimere Caribische regio. Indien goedgekeurd tijdens de volgende Conference of parties for the Cartagena Convention (COPS) later dit jaar op Aruba, biedt deze maatregel een wettelijk kader voor de instandhouding van de papegaaivis om de populatie op een optimaal niveau in de wijdere Cariben te verzekeren en te behouden.

Wilt u meer weten over de lokale papegaaivispopulaties? Bekijk de volgende gerelateerde artikelen:

Fish poop: an underappreciated food source for coral reef fishes?,

Recovery of Orbicella annularis corals from parrotfish predation,

Parrotfish key to reef survival,

https://www.gefcrew.org/carrcu/SPAWSTAC10/SPAW_STAC10_WG.43-INF.17_EN_Parrotfish_Inclusion.pdf\

 

DCNA

De Dutch Caribbean Nature Alliance (DCNA) ondersteunt wetenschapscommunicatie en outreach in de Nederlandse Caribische regio door natuurgerelateerde wetenschappelijke informatie breder beschikbaar te maken via onder meer de Dutch Caribbean Biodiversity Database, DCNA’s nieuwsplatform BioNews en de pers. Dit artikel bevat de resultaten van verschillende wetenschappelijke onderzoeken, maar de onderzoeken zelf zijn geen DCNA-onderzoeken. Aan de inhoud kunnen geen rechten worden ontleend. DCNA is niet aansprakelijk voor de inhoud en de indirecte gevolgen die voortvloeien uit het publiceren van dit artikel.

 

 

 

Gutu ta un piská ku ta bal mas ku djis unu ku nèchi kara so. E gutu averahe ta traha 90% di su bida riba tene ref di koral limpi. Ku nan boka skèrpi fásilmente nan ta raspa alga for di koral i baranka, loke ta esensial pa tene e refnan sano i salvo. Espesialmente aworakí ku tin faktornan importante manera evento di blikiamentu di koral i e malesa ‘Stony coral tissue loss disease (SCTLD)’ nan ta importante pa yuda ref di koral pa rekuperá i sigui krese. Ta bai konsiderá e aspekto di alsamentu di protekshon den region di Karibe den e siguiente Konferensia di Partido den e reunion di ‘Cartagena Convention (COPS)’ mas den kurso di e aña akí na Aruba. 

(Foto: Marion Haarsma)

Ref di Koral ta duna habitat importante na piská i otro animal. Hende tambe tin benefisio di e hopi servisionan di e ekosistema ku ref di koral ta krea, inkluso protekshon di kosta, kuminda i entrada for di turismo i peska. En realidat, ref di koral ta un di e fuentenan mas importante di entrada pa e islanan di Hulanda Karibense. 

 

Komedó di yerba important 

(Foto: Marion Haarsma)

Hèrbivor manera gutu tin un papel importante den mantenshon di ref di koral sano. Nan ta yuda pa mantené e balansa delikado denter di e ref dor di kome e (makro) alga, ku ta e kompetidor mas grandi pa espasio i lus. E gutu averahe ta pasa te ku 90% di su dia hasiendo ref limpi. No solamente e espesie di piská akí ta mantené e alga bou di kontrol, pero e hèrbivornan akí ta krea tambe espasio nobo pa yu di koral por ankra i krese. 

Ademas eliminando makro alga i promoviendo ankramentu i kresementu di koral, gutu ta un outor di eroshon biológiko ku ta produsí sedimento dor di raspa baranka pa kome alga i koral (ménos ku 10% di nan kuminda). Asina nan ta yuda resiklá nutriente i produsí “santu” pa áreanan (ku eroshon) na kosta. 

E rapòrt di ‘Global Coral Reef Monitoring Network (GCRMN)’ titulá “Status and Trends of Caribbean Coral Reefs / Status i Kurso di desaroyo di Ref di Koralnan Karibense: 1970-2012″ pa Jackson et al. (2014) a dokumentá tendensia di desaroyo kuantitativo di salubridat di ref di koral durante 43 aña den e region di Karibe amplio. E rapòrt ta mustra ku un di e faktornan mas grandi di dekadensia di ref di koral den Karibe ta e peska eksesivo di hèrbivor, partikularmente di gutu. 

 

Menasa 

(Foto: Steph Wear)

Gutu ta prosperá mas tantu den ekosistemanan di ref di koral saludabel. Pa e motibu ei e piská akí tin e mesun enemigunan ku ta krea menasa ku e enemigunnan di koral. Esakinan ta inkluí e efektonan negativo di kambio di klima, oumento di ásido (zür) den osean, polushon i malesa manera e ‘Stony coral tissue loss disease (SCTLD)’. Ademas, peska eksesivo por kaba ku populashonnan lokal di gutu. Investigashonnan ta mustra ku refnan ta mas saludabel i tin un kapasidat di resiliensia mas haltu kaminda ku gutu ta protehá. Esaki ta enfatisá e importansia di gutu pa refnan por rekuperá i krese di nobo despues di e menasanan akí. 

 

Protekshon di Gutu 

Na Hulanda Karibense – ta na Aruba ku Boneiru – tin lei i regulashon lokal pa protekshon di gutu. Na e islanan akí ta prohibí pa kohe, mata, heridá òf stroba nan. Afortunadamente pa e otro islanan na Karibe (Hulandes), Reino Hulandes, huntu Repúblika di Fransia, a entregá formalmente un proposishon pa inkluí tur gutu den e Anekso III di e protokòl ‘Specially Protected Areas and Wildlife (SPAW) Protocol’, un akuerdo regional pa protekshon i uso duradero di e biodiversidat marino den e Region di Karibe Amplio. Si akordá esaki durante e próksimo konferensia di partido pa e konvenshon ‘Cartagena Convention (COPS) IGM20/COP17’ mas den kurso di e aña akí na Aruba, e medida akí ta krea un kuadro legal pa konservashon di gutu pa sigurá i mantené e populashon di gutu na un nivel optimal den Karibe Amplio. 

 

Bo ke haña mas konosementu tokante populashonnan lokal di gutu? Chèk e siguiente artíkulonan ku laso: 

Fish poop: an underappreciated food source for coral reef fishes?, 

Recovery of Orbicella annularis corals from parrotfish predation, 

Parrotfish key to reef survival,

https://www.gefcrew.org/carrcu/SPAWSTAC10/SPAW_STAC10_WG.43-INF.17_EN_Parrotfish_Inclusion.pdf\  

 

DCNA 

Dutch Caribbean Nature Alliance (DCNA) ta sostené komunikashon sientífiko i presentashon na públiko den region Karibe Hulandes dor di hasi informashon sientífiko relashoná ku naturalesa mas ampliamente disponibel pa medio di entre otro e Dutch Caribbean Biodiversity Database, DCNA su plataforma di notisia BioNews i prensa. E kontenido akí ta kontené e resultadonan di diferente estudio sientífiko pero e estudionan mes no ta di DCNA. No por saka ningun derecho for di e kontenido. DCNA ku e publikashon no ta legalmente responsabel pa e kontenido i e impaktonan direkto/indirekto di e artíkulo akí. 

 

 

 

Gutu ta mas cu djis un cara bunita. E gutu promedio ta pasa te 90% di su dia limpiando e rifnan di coral. Su piknan afila ta permitie raspa kita e alganan  facilmente di e coralnan y e barancanan, loke ta esencial pa mantene e rifnan saludabel y prospero. Specialmente awor cu e principal factornan di stress, manera e eventonan di blankia coral y malesa di perdida di tehido di piedra di coral  SCTLD (Stony coral tissue loss disease), ta importante pa yuda e rifnan di coral recupera y bolbe crece. Lo considera un mayor proteccion den e region di Caribe durante e proximo Conferencia di e partinan pa e reunion di e Convencion di Cartagena (COPS) mas despues durante e aña aki na Aruba. 

(Foto: Marion Haarsma)

E rifnan di coral ta proporciona un habitat valioso pa pisca y otro bestia. Hende tambe ta beneficia di e hopi servicionan ecosistemico cu e rifnan di coral ta brinda, incluyendo proteccion di costa, alimento y e ingresonan di turismo y pesca. De facto, e rifnan di coral ta un di e fuentenan di ingreso mas importante pa e islanan di Caribe Hulandes. 

 

Comedo di yerba important 

(Foto: Marion Haarsma)

Herbivoro manera gutu ta hunga un papel fundamental den mantencion saludabel di e rifnan di coral. Nan ta yuda mantene e ekilibrio delicado dentro di e rifnan door di come alga (macro), cu ta e principal competido di e coralnan pa espacio y luz. E gutu promedio ta pasa hasta 90% di su dia limpiando rif. No solamente e especienan di pisca ta mantene e alganan bou di control, sino cu tambe e herbivoronan aki ta crea espacio nobo pa e coralnan baby pega y crece. 

Ademas di elimina e macroalganan y promove asentamento y crecemento di e coralnan, e gutunan tambe ta bioerosionado natural cu ta produci sedimento door di come yerba riba e barancanan, alga calcarea y coral (menos di 10 % di su alimento). Di e manera aki nan ta yuda recicla e nutrientenan y nan ta produci “santo” pa e zonanan di costa (erosiona). 

Global Coral Reef Monitoring Network (GCRMN) nan raport titula “Status and Trends of Caribbean Coral Reefs: 1970-2012″ pa Jackson et al. (2014) a documenta tendencia cuantitativa tocante salud di e rifnan di coral durante 43 aña den Caribe Mayor. E informe ta identifica cu un di e principal impulsornan di rechaso di e rifnan di coral den Caribe ta pesca excesivo di herbivoro, particularmente di gutu. 

 

Menasa 

(Foto: Steph Wear)

Gutu ta prospera miho den ecosistema di rif di coral saludabel. Por lo tanto, e piscanan ey ta suheto na e mesun menasanan cu e coralnan. Esaki ta inclui e efectonan negativo di cambio climatico, e acidificacion di ocean, e contaminacion y malesa manera e malesa di perdida di tehido di coral duro. Ademas, sobrepesca por caba hopi lihe cu poblacionnan local di gutu. Estudionan ta mustra cu e rifnan ta mas saludabel y tin un mayor capacidad di resiliencia di recuperacion na luganan unda e gutunan ta proteha. Esaki ta e importancia di gutu pa cu e rifnan por recupera y bolbe crece di e menasanan aki. 

 

Proteccion di gutu 

Den Caribe Hulandes -na Aruba y Boneiro- ta existi norma y reglamento local pa proteha tur gutu. Na e islanan aki ta prohibi pa gara, mata, herida of molestia e gutunan. Afortunadamente pa e demas islanan di Caribe (Hulandes), Reino Hulandes, hunto cu Republica di Francia a presenta formalmente un proposicion pa inclui tur e gutunan den Anexo III di Specially Protected Areas and Wildlife (SPAW) Protocol, (Protocol di Area y Bida Silvestre specialmente Proteha), un acuerdo regional acuerdo pa proteccion y uzo sostenibel di e biodiversidad costera y marino den e Region di Gran Caribe. Si  aproba esaki durante e proximo Conferencia di e Partinan pa e Convencion di Cartagena (COPS) IGM20/COP17 mas despues durante e aña aki  na Aruba, e medida aki ta proporciona un marco legal pa conservacion di gutu pa sigura y mantene e poblacion den un nivel optimo den Caribe Mayor. 

 

Bo kier siña mas tocante e poblacionnan local di gutu? Consulta e siguiente articulonan relaciona cu esaki: 

Fish poop: an underappreciated food source for coral reef fishes?, 

Recovery of Orbicella annularis corals from parrotfish predation, 

Parrotfish key to reef survival,

https://www.gefcrew.org/carrcu/SPAWSTAC10/SPAW_STAC10_WG.43-INF.17_EN_Parrotfish_Inclusion.pdf\  

 

 DCNA

Dutch Caribbean Nature Alliance (DCNA) (Aliansa pa Naturalesa di Caribe Hulandes) ta sostene comunicacion cientifico y divulgacion den region di Caribe Hulandes door di haci cu e informacion cientifico relaciona cu naturalesa ta mas disponibel a traves di, entre otro, Dutch Caribbean Biodiversity Database, (Base di Dato di Biodiversidad di Caribe Hulandes), plataforma di noticia BioNews di DCNA y prensa. E articulo aki ta contene resultado di varios estudio cientifico, pero e estudionan riba nan mes no ta estudionan di DCNA. Ningun derecho no por wordo deriva di e contenido. DCNA no ta responsabel pa e contenido y e impacto indirecto cu resulta di publicacion di e articulo aki. 

 

Published in BioNews 63

Abstract

Animals often occupy home ranges where they conduct daily activities. In many parrotfishes, large terminal phase (TP) males defend their diurnal (i.e., daytime) home ranges as intraspecific territories occupied by harems of initial phase (IP) females. However, we know relatively little about the exclusivity and spatial stability of these territories. We investigated diurnal home range behavior in several TPs and IPs of five common Caribbean parrotfish species on the fringing coral reefs of Bonaire, Caribbean Netherlands. We computed parrotfish home ranges to investigate differences in space use and then quantified spatial overlap of home ranges between spatially co-occurring TPs to investigate exclusivity. We also quantified the spatial overlap of home ranges estimated from repeat tracks of a few TPs to investigate their spatial stability. We then discussed these results in the context of parrotfish social behavior. Home range sizes differed significantly among species. Spatial overlap between home ranges was lower for intraspecific than interspecific pairs of TPs. Focal TPs frequently engaged in agonistic interactions with intraspecific parrotfish and interacted longest with intraspecific TP parrotfish. This behavior suggests that exclusionary agonistic interactions may contribute to the observed patterns of low spatial overlap between home ranges. The spatial overlap of home ranges estimated from repeated tracks of several TPs of three study species was high, suggesting that home ranges were spatially stable for at least 1 month. Taken together, our results provide strong evidence that daytime parrotfish space use is constrained within fixed intraspecific territories in which territory holders have nearly exclusive access to resources. Grazing by parrotfishes maintains benthic reef substrates in early successional states that are conducive to coral larval settlement and recruitment. Behavioral constraints on parrotfish space use may drive spatial heterogeneity in grazing pressure and affect local patterns of benthic community assembly. A thorough understanding of the spatial ecology of parrotfishes is, therefore, necessary to elucidate their functional roles on coral reefs.

A new study by researchers from the University of Texas and California Polytechnic State University documented herbivorous fishes feeding on fish fecal pellets off the coast of Bonaire.  This has never been recorded in the Caribbean before and provides a deeper understanding of nutrient recycling and insight into the diverse diets of fishes who work to keep the local coral reefs healthy.

Blue parrotfish (Scarus coeruleus). Photo credit: Marion Haarsma

Coral reefs are one of the most diverse ecosystems on the planet, but they are also limited in nutrients. So, nutrient recycling is a vital part of supporting such reef organisms and their biodiversity. Organisms can’t process all the nutrients from the food they eat, so some of these nutrients come out in their poop. A new study documented a unique upcycling technique, previously unknown within the Caribbean, herbivorous fish feeding on fish feces.

Parrotfishes and surgeonfishes are often praised as the great caretakers of coral reefs, feeding on reef algae and keeping overgrowth in check, which indirectly promotes healthy coral recruitment and growth.  Although it was previously known that Caribbean parrotfishes and surgeonfishes also fed off other food sources, such as cyanobacteria, sponges, and even corals themselves, a recent study added fish feces to this list.

The Study

This collaborative effort was co-led by Hannah Rempel, a Ph.D. student from University of Texas Marine Science Institute and Abigail Siebert, a former undergraduate student from California Polytechnic State University. They studied the foraging rates of parrotfishes and surgeonfishes on fish fecal matter. Because they found that over 99% of feces they consumed were from the Brown Chromis (Chromis multilineata), a plankton eating fish, they also observed Brown Chromis feces to see what other reef fish ate them and studied the nutritional value of these feces. The study was conducted in 2019 between June and September, across six dive sites along the western shores of Bonaire.  This research is the first of its kind within the Caribbean and paves the way for continued exploration into the topic.

Fecal pellet. Photo credit: Hannah Rempel

The Results

Throughout this study, researchers documented that almost 85% of the observed fecal pellets were ingested by fish with over 90% consumed by parrotfish and surgeonfishes alone. “Compared to algae, these fecal pellets are rich in a number of important micronutrients. Our findings suggest they may be an important nutritional supplement in the diets of these fishes” stated Rempel. Taking a closer look at the fecal matter itself, researchers found that these pellets had higher values of proteins, carbohydrates, total calories, and important micronutrients when compared to most algae.  Therefore, consuming fecal matter may play an important role in nutrient transfer within the marine environment.

Future Research

Understanding the intricate dynamics within coral reefs provides information management authorities need to safeguard these environments more effectively. These results highlight the importance of the consumption of fecal matter in upcycling micronutrients, although there is still much to be learned about the nutritional content of other food sources, such as algae mats, cyanobacteria, sponges and corals.  Fish feces may play a vital role in nutrient supply within the reef environment, emphasizing the need for further insight into this topic moving forward.

For more information you can find the full report on the DCBD by using the link below.

More info in the Dutch Caribbean Biodiversity Database

 

 

Published in BioNews 53

Parrotfishes can often be observed consuming fish feces on coral reefs. Our recent study highlights the nutritional value of these feces to parrotfishes.  Four of the five most common speciesa t our study sites (Bonaire, Caribbean Netherlands) consumed feces, mostly from Chromis multilineata. Despite being infrequent (<4% total bites), we estimate that coprophagy may contribute ~27% of the carbon obtained by parrotifhses while foraging on preferred benthic substrates. Chromis feces also have higher protein and lipid conetents and lower C:N:P ratios than other foraging targets (algae and cyanobaceteria). Coprophagy is, thereofre, likely an important nad understudied component of parrotfish nutrition.

 

Read more at: https://www.jstor.org/stable/48657233

 

https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/ecy.3657

 

Abstract

Parrotfishes and surgeonfishes are major Caribbean herbivores that primarily graze reef algae and thereby play an important functional role in indirectly promoting coral recruitment and growth. Yet, an emerging body of research suggests that these nominal herbivores graze on a diverse array of other food sources and researchers have questioned whether they may target more nutrient-dense foods growing within or upon algae, such as cyanobacteria. In this study, we investigated the speciesspecific foraging rates of parrotfishes and surgeonfishes on Brown Chromis (Chromis multilineata) fecal pellets compared to other major dietary items. We found that almost 85% of observed fecal pellets were ingested by fishes and that over 90% of ingested fecal pellets were consumed by parrotfishes and surgeonfishes alone. While there were species-specific differences in the levels of feces consumption (coprophagy), we found that all three surgeonfishes (Acanthurus chirurgus, A. coeruleus, and A. tractus) and six of the nine of parrotfish species surveyed (Scarus coeruleus, S. iseri, S. taeniopterus, S. vetula, Sparisoma aurofrenatum, and S. viride) consumed C. multilineata feces. To better understand the nutritional value of this behavior, we analyzed the composition of proteins, lipids, carbohydrates, total calories, and micronutrients in C. multilineata fecal pellets and compared these to published values for other food sources targeted by these fishes. Our findings suggest that these fecal pellets may have higher values of proteins, carbohydrates, total calories, and important micronutrients, such as phosphorus, compared to various macroalgae and the epilithic algae matrix, though comparable or lower values compared to cyanobacteria. To our knowledge, this is the first study to document coprophagy by tropical herbivorous fishes in the Caribbean region. This research advances our understanding of the foraging ecology of nominally herbivorous fishes and highlights the importance of fish feces as a nutritional resource on coral reefs.

The direct and indirect impacts of the increase in human population, in particular the growing demand for food, as well as various aspects of climate change pose threats to the abundance of parrotfishes (Scarinae), the main coral reef grazers. One way to reduce fishing is by forming marine protected area (MPA). MPAs tend to increase the abundance of marine fish. Well-managed MPA, with effective protection from fishing, could also benefit sex-changing fish populations. The objectives of this research are to assess effects of MPAs on parrotfish abundance and biomass and how do parrotfish abundance and size in the different life phases differ between sites within MPAs and outside MPAs. Fish surveys were conducted in eight Caribbean countries (Antigua, Bonaire, Barbados, Curaçao, Dominican Republic, Jamaica, St. Lucia and St. Vincent and Grenadines (SVG)) using an underwater visual census technique. The differences between parrotfish density and size within and outside MPAs were assessed. Mean parrotfish numerical density was slightly higher at MPA sites than at non-MPA sites but this was not significant. A significant difference was found between parrotfish biomass within and without the MPAs. The abundance biomass comparison (ABC) results showed that out of 33 MPA sites, 79% had a positive index and 21% a negative W-index value. In contrast, only 49% of non-MPA sites surveyed had a positive W-index. Sites within an MPA generally had higher mean parrotfish sizes than those outside the MPA, except for the juvenile phase. The present results reinforce the belief that parrotfish abundance and biomass, which where depleted by fishing, can be increased through applying significant levels of protection. However further research is needed on the effectiveness and duration of protection which are necessary to produce desired levels of improvement in parrotfish abundance, biomass and size.