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Impact and management (efforts) of Sargassum in the mexican CaribbeanSargassum Scientific GroupReef Systems Research UnitInstituto de Ciencias del Mar y LimnologaNational Autonomous University of Mexico (UNAM)

Latin America and Caribbean Sea Large Marine Ecosystems SymposiumSpecial working group session to analyse the presence of Sargassum in coastal areas of the Wider Caribbean Region8 September 2015

Impact

Puerto Morelos beach: RE RodriguezCancun hotel zone: webcamManagement

Akumal: MA MaldonadoPunta Caracol: BI van TussenbroekPuerto Morelos: BI van Tussenbroek

Estimated harvested SargassumAugust 2015Basado en Informacin de SECRETARA DE ECOLOGA Y MEDIO AMBIENTE DEL ESTADO DE QUINTANA ROODisposal

Abandoned calcareous sand mining pits were assigned to receive 80% of the collected Sargassum.But they havent received any!Leachates H2S CH4Sea

Ground water ContaminationTechnical Scientific CommitteeQuintana RooLocal authorities, Representatives Society and Research Institutions

Tasks: Document harvest and disposal of Sargassum Elaborate databases Define guidelines for: Containment Collection in the sea Transport Disposal and use/resource exploitation Evaluate pilot projects in: Puerto Morelos, Cancn, Akumal y Tulum Advise authorities in decision makingSub-committes: 1. Scientific/technical, 2. Harvest, 3. Dispoasal & treatment, 4. Environmental regulations, 5. Economical, 6. Outreach/communicationWhy now?Historical arrivals:Sargasso Sea (7-10 x106 t)& Sargassum Loop System

It is not known whether or how Sargassum escaped from the Sargassum loop system and arrived at the North Equatorial Recirculation Region (GCC???) Knowledge about the origin of Sargassum will indicate whether the massive arrival to certain Caribbean beaches is incidental or permanent

New arrivals since 2011(MERIS satellite images: May, July, September 2011)http://seas-forecast.com/Nature504;doi:10.1038/nature12860Why so much?Growth rate and nutrientsThere is a direct relation between photosynthesis (growth) and available nutrientsLapointe (1986)

Sargassum natans(dominant species of original Sargasso Sea)

Sargassum fluitans(dominantes recent massive arrivals)When nutrients are high, Sargassum can multiply its weight in 12-20 daysIf caught in the North Atlantic Recirculation Region (NARR), Sargassum has a lot of time to grow

http://en.wikipedia.org/wiki/File:Seawifs_global_biosphere.jpgThe original Sargasso Sea is nutrient poorOceanic nutrient distributionMississippiOrinoco & AmazonThere are more nutrients in the NARR

Effect of regional eutrophication?There are hardly any pristine coastal areas left in the Caribbean: principal causes for human-induced changes in seagrass beds were eutrofication and decreasing water clarityjournals.plos.org/plosone/article?id=10.1371/journal.pone.0090600Massive accumulation of seaweed in tide line (with some dead fauna)

H2S (smell and potential health hazards)

Interferes with turtle nesting & hatching

Harvesting from beach causes beach erosion

Impact on coastal ecosystemsBeachAugust 2015 (collected from beaches: Benito Juarez-Tulum)12169 m3 Sargassum / km 1022 dry t /km 17275 kg N / km(1 m3 84 kg; N content Sargassum= 16.9 mg /g, Hanson 1977)

Rebolledo (CICY): N influx from aquifer into the sea2397 kg N /yr / km

Preliminary insights into the impact on marine coastal ecosystemsEutrophication?We do not know:proportion of Sargassum is retained in the systems proportion of N (P or other nutrients) in Sargassum is reminineralized and available for growth of primary producersPreliminary insights into the impact on marine coastal ecosystemsLight reductionWe do not know the permanent effects of light reduction on the coastal community

If Sargassum is not cleared from the beach(10-100 m wide) coastal fringes suffer from brown tides:

Puerto Morelos: BI van TussenbroekPto Morelos: GM Barba SantosNear the beach: H2S production can only occur in anoxic conditions

Preliminary insights into the impact on marine coastal ecosystemsOxygenThese are very preliminary data in a well-flushed system!!!Oxygen levels in the sea may be much lower in calmer areas with less water mixing

Brown tide: Light reduction & accumulation of POM (resulting in increased bacterial activity) reduces O2 in waterPuerto Morelos:Pto Morelos: BI van Tussenbroek

Preliminary insights into the impact on marine coastal ecosystems Submersed coastal vegetation

beforebeforebeforebeforebrown tidebrown tidebrown tidebrown tideImpressions from Pto. MorelosBefore and during the brown tideWe need to study changes in the vegetation: loss of seagrasses near the shoreline may result in beach erosionAll photos: BI van TussenbroekPreliminary insights into the impact on marine coastal ecosystems Introduction of faunaFechaMunicipioLocalidadEn Mar o Playa?Vivo o Muerto?FotografoFotoGrupoGeneroEspecieIdentific07/01/2015Benito JurezPuerto MorelosPlayaMuertoHoracio OcampoFalse PecesHistriohistrioMC Rosa Rodrguez07/01/2015Benito JurezPuerto MorelosPlayaMuertoHoracio OcampoFalse Peces07/01/2015Benito JurezPuerto MorelosPlayaMuertoHoracio OcampoFalse Peces07/01/2015Benito JurezPuerto MorelosPlayaVivoHoracio OcampoFalse EquinodermoHolothuriaarenicolaDr. Francisco Sols

Google database by Rosa Rodriguez: https://docs.google.com/spreadsheets/

The floating masses of Sargassum have a diverse fauna, and are bound to change the faunal communities throughout the Caribbean; but how?Our lack of knowledge concerning the massive arrivals of Sargassum in the Caribbean impedes effective mitigation and management

Effective (longer-term) measures can only be implemented if we know whether these arrivals are incidental or permanent

Technical studies into harvesting techniques, disposal and use should be implemented immediately considering the impact of this phenomenon on the regional economy

Scientific information concerning the effects on coastal ecosystems of the massive arrivals of Sargassum and possible harvesting are urgently required for adequate ecosystem managementResearchOrigin of Sargassum Call for multidisciplinary/international scientific research projects Satellite imaging (o.a. University of Galveston, SEAS-Forecast)Ocean modellingEstablish the relation between abundance time and nutrients (and other possible factors)

Concentration of information on massive beaching of Sargassum throughout the Caribbean Data management center and open access databases (a.o. Pelagic Sargassum in the Caribbean, Un. Southern Mississippi)

Knowledge whether these massive arrivals are incidental or permanentEcosystem services analysis may reveal willingness to pay and facilitate funding in a coordinated manner (o.a. local governments, Caribbean Hotel & Tourism Association)

Based on findings of origin and into spatial and temporal patterns of massive beaching: Establish an effective early warning system (a.o. SEAS-Forecast, Texas A&M)Research into effective harvesting (preferably at sea) on local and/or regional

Research into the disposal and use of Sargassum on local and/or regional scale Study into environmental impact of different ways of disposal (governments)Use as fertilizer/compost/landfill/biogas/supplemental fodder/alginates etc.scale (e.g. local private initiatives at some islands, some hotels e.g. Moon Palace)

2. Technical studies into harvesting techniques and effective disposal and useResearch into impact on beaches

(Crowd-sourced) webcams of beaches (e.g. SEAS-forcast)Erosion (when Sargassum is harvested from the beaches)Call for scientific research projects Effects on health Call for scientific research projects into the decay and associated bacterial activity on beached SargassumEffect on turtle nesting and hatchingCensus of turtle nesting(NGOs or governmental agencies)Call for scientific research projects

3. Scientific information concerning the impact on coastal ecosystems Research into the impact of Sargassum on faunaFisheries Database of Sargassum associated fauna (e.g. Naturalis, CONABIO)Call for scientific research projects Overall changes in faunaStudy into the effects of harvesting Sargassum at sea

Research into the impact on marine coastal systems (water clarity/nutrients/oxygen/changes in biota) - Call for scientific research projectsNear shore ecosystems (effect of brown tide)Coral reef systems3. Scientific information concerning the impact on coastal ecosystems (cont.)There are many local initiatives to mitigate the massive arrival/beaching of Sargassum

However, the causes and the effects of this phenomenon transcend local boundaries and require a coordinated regional approach in order to fully effective

Regional organizations such as LMEs may play a role in such a coordinated regional approach and facilitate search for the funding of scientific projectsResearch

The direct threat of Sargassum on the Caribbean coastal ecosystems and regional economy offers a unique opportunity for international collaboration among governments, society and thescientific community

This may raise overall awareness of a more sustainable exploitation of our resources