Climate change

Nederlands below.

A joint experiment between WWF-Mexico and STINAPA Bonaire found that vegetables grown in soil enriched with sargassum had higher levels of arsenic and cadmium, heavy metals that can be toxic to humans and animals.  Researchers warn that sargassum should not be used to compliment animal fodder, nor used as a fertilizer for consumables until further investigated.

Sargassum influx in Lac Cai

Sargassum is a floating brown seaweed that plays several important ecological roles. Although sargassum occurs naturally, due to shifting ocean currents and increased pollution, the Atlantic is experiencing episodic sargassum blooms.  Since 2011, the Caribbean has experienced several significant sargassum events, leading to a number of social, environmental and economic issues, particularly in the hospitality and fisheries sectors.  Sargassum influxes threaten the already fragile coral reefs, mangroves and seagrass beds.

The Study

To better understand the impact of disposed sargassum, a joint project between WWF-Mexico and STINAPA Bonaire explored whether sargassum-enriched fertilizer promoted faster seed development and if any heavy metals were detectable in the vegetables after harvest. Two planter boxes were used, one filled with 50/50 dried sargassum and potting soil and one with only potting soil.

The Results

Sargassum enriched soil testing set up

Although, in general, there appeared to be no significant physical differences (shape or quantity of vegetable production) between plants grown with or without the presence of sargassum, samples analyzed at the Radboud University laboratory found that arsenic levels were higher in vegetables grown in soil with sargassum. More specifically, bok choy had 37 times, zucchini 21 times, spinach 4 times and soil 13.5 times more arsenic than their counterparts grown in plain potting soil.  Cadmium levels were also higher in plants grown in sargassum enriched soil, with chemical analysis showing bok choy having 2.5 times, zucchini with 3 times, spinach with 1.3 times and soil with 2.7 times the amount of cadmium than samples without sargassum enrichment.

Furthermore, a Wageningen University and Research report titled “Opportunities for valorization of pelagic Sargassum in the Dutch Caribbean”, analyzed sargassum from the same source and found it to have high levels of heavy metals.  This full report is available from the Wageningen University and Research website (https://edepot.wur.nl/543797).

Implications

Decomposing sargassum in water

The health implications of these findings are still unclear. Arsenic can take several forms, namely organic and inorganic, where organic levels can be much higher before negative impacts are observed in people.  It should be noted that the European Food Safety Authority (EFSA) has not yet set official thresholds for arsenic. In fact, the EFSA Panel on Contaminants in the Food Chain (CONTAM) published data in 2010 which stated that there are no ‘safe’ levels of arsenic.  Long term ingestion of inorganic arsenic has been connected to skin lesions, cancer, developmental toxicity, neurotoxicity, cardiovascular disease, abnormal glucose metabolism and diabetes (CONTAM, 2010). More research is needed to understand impacts of these higher levels of heavy metals and the long -term effects when ingested.

As influxes of sargassum are becoming increasingly common, countries and individuals will search for innovative ways to use and dispose of this nuisance. Already, some reports have highlighted its use as a building material, animal fodder or fertilizer for home gardens. Until the health implications are more widely understood, it would be wise to limit sargassum use to non-consumable options.  This leaves the door open for sargassum to be used as building material (dried and pressed into bricks), biofuel or perhaps fertilizer for decorative plants or construction material, such as bamboo.

Submitted by: Jessica Johnson and Sabine Engel, researchers for STINAPA. This project was funded by WWF-Netherlands and received support from Radboud University.

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Nederlands

Zware metalen in sargassum-mest worden door planten opgenomen

De bevindingen van een experiment uitgevoerd door STINAPA in het kader van een gezamenlijk project met WWF Mexico tonen aan dat grond verbeterd met sargassum hogere arseeen (As) en cadmium (Cd) waardes heeft. Arseen en cadmium zijn zware metalen die schadelijk zijn voor mens en dier. De onderzoekers waarschuwen dat sargassum niet gebruikt moet worden als aanvulling voor dier voedsel of als bemesting van groenten, voordat verder onderzoek heeft plaatsgevonden.

Sargassum bij Lac, Bonaire

Sargassum is een drijvend bruinwier dat een aantal belangrijke ecologische functies vervult. Sargassum komt natuurlijk voor, maar door veranderde zeestromingen en toegenomen vervuiling komen er nu periodieke sargassum ‘blooms’ (woekeringen) voor. Sinds 2011 zijn er in de Caraïben verschillende heftige sargassum ‘blooms’ geweest die gevolgen hadden op sociaal-, milieu- en economische gebied, voornamelijk in de horeca, toeristen en visserij sector. De periodieke sargassum aanvoer bedreigt daarnaast ook de toch al kwetsbare koraalriffen, mangroves en zeegras bedden.

De studie

Om meer te weten over het lot of de mogelijke toepassing van het afgevoerde sargassum werd in een gezamenlijk WWF Mexico – Bonaire project door STINAPA onderzocht of planten beter ontkiemden op grond waar sargassum-mest aan toe was gevoegd, en of de zware metalen voor kwamen in de geoogste planten. Twee plantenbedden werden klaargemaakt: één met potgrond, en één met 50/50 potgrond en gedroogd sargassum.

De resultaten

Het kweek experiment

Over het algemeen was er geen zichtbaar verschil tussen de planten gekweekt in de twee bedden maar monsters geanalyseerd aan de Radboud Universiteit toonden hogere arseen waardes aan in groentes uit de bedden met sargassum. Om precies te zijn, bok choy had 37 keer, zucchini 21 keer, malabar spinazie 4 keer, en het groeimedium potgrond sargassum 13.5 keer meer arseen dan de planten en grond uit de bedden met alleen potgrond. Het cadmium gehalte was ook hoger in planten die gekweekt waren in de ‘sargassum’ grond. Bij bok choy was dat 2,5 keer zoveel, zucchini 3 maal spinazie 1,3 maal en het medium 2,7 keer de hoeveelheid cadmium dan de controle planten.

Aan de Wageningen Universiteit werden monsters sargassum van dezelfde bron onderzocht in het kader van de studie “Opportunities for valorization of pelagic Sargassum in the Dutch Caribbean”, en werden ook hoge waardes voor zware metalen aangetroffen. Het volledige rapport is te vinden op de site van Wageningen University and Research (https://edepot.wur.nl/543797)

Implicaties

De gezondheids implicaties zijn nog niet helemaal duidelijk. Er zijn verschillende organische en anorganische vormen van arseen. Pas bij hogere waardes van organisch arseen worden negatieve gevolgen waargenomen voor mensen. De Europese Voedsel Veiligheid authoriteit (EFSA) heeft nog geen drempelwaardes vastgesteld. In feite publiceerde het EFSA Panel Verontreinigingen in de Voedselketen (EFSA Contaminants in the Food Chain (CONTAM)) in 2010 gegevens en stelde dat er geen ‘veilige’ arseen waarden zijn. Verband is gelegd tussen langdurige blootstelling aan anorganisch arseen en huidafwijkingen, kanker, ontwikkelingstoxiciteit, neurologische toxiciteit, cardiovasculaire ziektes, abnormale glucose vertering en diabetes (CONTAM, 2010). Er is meer onderzoek nodig om te bepalen wat de effecten zijn van deze zware metalen bij langdurige blootstelling.

Nu het op de kust ophopen van sargassum steeds vaker voorkomt zoeken landen en organisaties naar innovatieve manieren om van deze sargassum-overlast af te komen. Er zijn al publicaties die hebben aangegeven dat sargassum gebruikt kan worden als bouwmateriaal, veevoer of als huis & tuin grondverbeteraar. Maar zolang de gezondheidseffecten niet duidelijk zijn is het verstandig om sargassum niet te gebruiken voor voedselproductie. Het biedt dus alleen mogelijkheden voor bouwmateriaal (gedroogd en in blokken samengeperst), biofuel en misschien bemesting voor decoratieve planten of bouwmateriaal zoals bamboe.

Samengesteld door Jessica Johnson en Sabine Engel, onderzoekers voor STINAPA. Dit project is gefinancierd door WWF – Nederland, met bijdrages van de Radboud Universiteit.

Published in BioNews 54

May 16th 2022- Today the DCNA launches a Climate Action Plan for the Dutch Caribbean. This plan provide concrete recommendations for all our islands on both climate adaptation and mitigation strategies to combat climate change effects.

Photo credit: A.O. Debrot

Caribbean islands are at the forefront of the climate crisis, with effects already starting to become noticeable in the region. Experts have warned, including in the recently released IPCC Sixth Assessment Report, that we have just ten years left to avert the worst climate impacts but that this will require decisive action, both in terms of adaptation and mitigation strategies.

The Dutch Caribbean islands are particularly vulnerable to climate change impacts. People’s lives and livelihoods as well as most economic activities are located near coastal areas while the region’s unique nature is already under pressure from human impacts. This is compounded by the fact that, due to the island’s small geographic area and limited human capacity, the resilience to recover from disastrous events is low.

As stewards of nature in the Dutch Caribbean the parks united in the DCNA see first-hand how the changing climate is already affecting the islands. We see it as vital for all the governments, both in the Netherlands and in the Dutch Caribbean,  to embrace this plan and collaborate with local stakeholders on the implementation of a climate smart future for our beautiful islands and their communities.

As the impacts of climate change worsen, it is essential that greater efforts are placed on enhancing the implementation of mitigation and adaptation strategies in the Dutch Caribbean. Sustainable development and combating climate change require an integrated approach that prioritises, protection of nature, energy independence, sustainable tourism industry, and a diverse blue economy. But most importantly this needs to be a joint effort where countries work together to strengthen each other’s effort and resolve.

Read the Dutch Caribbean Climate Action Plan in English.
Or in Dutch.

Published in BioNews 54

Caribbean flora and fauna have always coped with the destructive forces of hurricanes. However, climate change leading to an increase in their frequency and strength, and because many species have declined in abundance due to anthropogenic causes, a better understanding of how hurricanes effect local populations is essential.

The Quill before and after Hurricane Irma. Photo credit: Hannah Madden

2017 Hurricane Season

The 2017 Caribbean hurricane season was the most intense recorded to date. Both Irma and Maria, category-5 hurricanes, closely passed Sint Eustatius and caused major destruction on the island; reported in this Nature Today article. Although immediately after the storms it was clear that trees were heavily affected and mostly defoliated, understanding which species were affected and to what extent requires time for data collection and comparison. Since 2017, several studies have provided pieces of information in order to understand how local populations coped, or not, with the 2017 hurricane season.

Since 2017, researchers found that >90% of all trees were defoliated by more than ¾, and that especially trees at higher elevations (such as on the Quill volcano) were affected more severely. Another study that focused on the Bridled Quail-dove (Geotrygon mystacea), demonstrated that the population declined by 77% in 2019 compared to pre-hurricane levels. A follow-up study in 2021 (not yet published) recorded a further decline to just 125 individuals, and the Bridled Quail-dove will likely be re-assessed by the IUCN.

Reptiles

Focusing on reptile species, a novel study further aids our understanding of the ecosystem-wide impact that the 2017-hurricane season had on Statian biodiversity:

The new study, focusing on the Critically Endangered Lesser Antillean iguana (Iguana delicatissima), shows that its population decreased by at least 20% during 2017. Comparing sighting and survey data from 2017–2018, the authors found a decrease in both the occupancy and population size of the iguana species. Importantly, no recovery was observed in 2019, suggesting that this already small population needs multiple consecutive years without major hurricanes to recover. Interestingly, similar to Statia’s forests, iguanas at higher elevations were found to have been affected more severely.

Letter Antillean Iguana. Photo credit: Philippa King

Importance

Small islands such as Sint Eustatius are home to declining populations of rare and endangered species. In many cases, these isolated populations are unable to migrate between islands and thus populations can only increase in size locally. These new studies highlight the need to improve habitat quality and lower anthropogenic threats to optimize the natural recovery of these species. Ideally, at least for population increase could be aided by a local head-starting project where baby iguanas are nourished in temporary captivity and released once they are larger and more likely to survive.

You can find the full study here entitled “Hurricane-induced population decrease in a Critically Endangered long-lived reptile” using the DCBD link below.

More info in the Dutch Caribbean Biodiversity Database
 

Downloads & links >

Published in BioNews 54

Veerkracht tegen klimaatverandering verloren door stapeling van drukfactoren

- stijgingen in de lucht

- en zeewatertemperatuur

- zeespiegelstijging

- verzuring van de zee

- toenemende verdroging van het klimaat

- woekerende invasieve soorten en tropische ziekten

- afname in biodiversiteit

- toenemend frequentie en kracht van orkanen

See also https://www.dcbd.nl/document/%E2%80%98nature-based-solutions%E2%80%99-zi...

Achtergrond

Caribisch Nederland (Bonaire, Saba en St. Eustatius) en de Koninkrijkspartners Aruba, Curaçao en Sint Maarten worden nu en in de komende decennia met toenemende mate geconfronteerd met zware nadelige effecten van klimaatverandering. Die effecten zijn onder andere: - stijging van de zeespiegel - stijgingen in de lucht- en zeewatertemperatuur - toenemende verdroging van het klimaat - woekerende invasieve soorten en tropische ziekten - afname in biodiversiteit - toenemend frequentie en kracht van orkanen. Laaggelegen delen van historische steden zoals Willemstad (Curaçao) en Philipsburg (St. Maarten) en overige aan de kust gelegen infrastructuur zullen zonder ingrijpen uiteindelijk aan de zee moeten worden prijsgegeven. De eilanden beschikken over een rijke biodiversiteit met veel soorten en ondersoorten die niet of nagenoeg nergens op andere plekken voorkomen. Deze soorten zijn vaak bijzonder kwetsbaar voor invasieve soorten en veranderingen in het milieu, waaronder ook die veroorzaakt door klimaatverandering. Omdat de natuur slecht in stand is gehouden, is er sprake van een sterk verminderde veerkracht bij klimaatverandering.

In het verleden is menigmaal gewezen op de noodzaak om een actief klimaatbeleid en een adaptatiestrategie te ontwikkelen en implementeren voor Caribisch Nederland. Helaas heeft het daar tot nu toe aan ontbroken. Deze noodzaak is onlangs opnieuw benadrukt door recente standpunten van de Dutch Caribbean Nature Alliance (DCNA, 2020) en Greenpeace Nederland (2022), en door een uitgebreide analyse de Vrije Universiteit Amsterdam (2022) van de te verwachten gevolgen van klimaatverandering voor Bonaire.

See also https://www.dcbd.nl/document/powerpoint-httpswwwdcbdnldocumente28098natu...

Abstract

Worldwide, coral reef health is declining rapidly due to both global stressors (climate change) and local stressors (pollution). Reef maintenance on Curaçao focusses on reducing local stressors including terrestrial pollution. One f low path for terrestrial pollution is via submarine groundwater discharge (SGD). Yet, on the island of Curaçao these hotspots of submarine groundwater discharge have not yet been located, let stand quantified. With this research we aimed to increase our understanding of groundwater flow on the island. This will serve as a foothold for future SGD research. To do so, we have conducted 9 electrical resistivity tomography (ERT) measurements to understand (1) the heterogeneity of the lava formation, the main aquifer, (2) the saltwater-fresh water interface at the coast, and (3) the groundwater flow at geological interfaces. To assist in the interpretation of the data we measured groundwater levels and the discharge of Hato spring, in addition to observing local geological outcrops. We discovered that the lava formation is a very heterogenous aquifer due to variety in degree of weathering of the pillow basalt. As a result of the heterogenous permeability, the extent of seawater intrusion in the coastal lava formation is strongly variable. Yet, the lava formation does form a better barrier for sea-fresh water mixing than the limestone terraces. The midden formation (sedimentary rock) forms a thin aquifer near the surface. And, at the interface of lava and midden formation, the groundwater flow is hampered. As a result, the groundwater is confined within the lava formation until the lava formations reservoir “overflows”. The same occurs at the interface of the lava formation and the diorite intrusion. The next step in SGD research is quantifying the seaward groundwater flux where the lava formation is in direct contact with the sea or limestone formation. Here seaward groundwater flow is not hampered by the midden formation or the intrusion and thus forms hotspots of Submarine (polluted) Groundwater Discharge.

Abstract

Small Islands (SIs) often have a small capacity to resist or recover from the increasing impacts of climate change and, therefore, increasing climate resilience is necessary. However, knowledge and research on climate resilience, especially in the context of (Caribbean) SIs are limited in number and quality, although imperative for increasing it. Additionally, research, while proven beneficial, often overlooks the household-level. Therefore, this study researched household climate resilience (HCR) in Caribbean SI-context –in this case Bonaire. Since the aspects determining HCR depend on geographic context, this contextwas first studied for Bonaire. Through 13 key-informant interviews, complemented by desk research, the main climate vulnerabilities, their impact on Bonaire and its households, and the aspects making Bonairean households resilient for these were identified. These aspects were used as indicators to form a composite score measuring HCR through online household surveys. Hereby, the barriers to HCR and differences in HCR between socio-demographic groups were identified. Results showed an average HCR-score for the sample (N=183) of .455 out of 1 (SD=.11) –indicating HCR is not low, but also not high. The following aspects negatively contributed to HCR: expected damage to homes, amount of savings, insurance covering damage from climate change (vulnerabilities), incomes, dependent income sources, vulnerable neighbourhoods, alternatives to electricity, water, and food, social resilience, community response, government response, awareness of climate change, information and education on climate change impacts, and steps to prepare for this. Furthermore, the following households are less inclined to be climate resilient: bigger households, households with high kid ratios, households with younger household heads, households speaking fewer languages, households not fluently speaking English, and households with a higher level of obtained education.This study knows limitations that possibly impacted these results, like the limited representativeness of the household sample. Although this study adds to the knowledge base of SI-context HCR, additional research is beneficial. Therefore, recommendations forfurther research are provided. The same goes for policy recommendations.

For more information, please contact Nina Zander nina.p.zander@gmail.com.

Please also see:

Nina Zander's Masters Thesis https://www.dcbd.nl/document/household-resilience-climate-change-vulnerabilities-case-study-bonaire

DCNA Policy Brief https://www.dcbd.nl/document/small-islands-%E2%80%93-large-climate-change-challenges-household-resilience-climate-change

Main Findings

The main climate change vulnerabilities for Bonaire are: an increase in the intensity of hurricanes and tropical storms, an increase in the number and extent of flood events, and an increase in the occurrence of extreme weather

• These impact Bonaire’s natural systems (e.g., destruction of coastal and marine ecosystems and terrestrial environments) and socio-economic systems (e.g., health, income, and food availability) – and thus negatively impact households.

• The average score of the household sample indicates that HCR in Bonaire is not particularly low, but also not high.

• Especially the following drivers of household climate resilience seem to be limited in Bonaire: expected damage to homes, amount of savings, insurance covering damage from climate change (vulnerabilities), dependent income sources, incomes, vulnerable neighbourhoods, alternatives to electricity, water, and food, social resilience, community response, government response, awareness of climate change, information and education on climate change impacts and steps to prepare for this, and steps taken to prepare for this.

• The following households are less inclined to be climate resilient: (possibly) bigger households, households with high kid ratios, households with younger household heads, (possibly) households speaking fewer languages, households not fluently speaking English, and households with a higher level of obtained education.

Recommendations

• Create an action plan in which policy directly aimed at increasing (household) climate resilience is formulated. This should at least include policy to:

>Keep investing in the protection and recovery of Bonaire’s nature

>Create awareness >Increase the availability of insurance covering damage from climate change (vulnerabilities)

>Provide financial assistance to help households prepare for climate change (vulnerabilities)

>Provide income generating opportunities and diversify the economy.

• Incorporate climate change (resiliency) in the design of policy on other themes.

• Increase cooperation• Involve the local community

• Conduct additional research

For more information, please contact Nina Zander nina.p.zander@gmail.com.

Please also see:

Nina Zander's Masters Thesis https://www.dcbd.nl/document/household-resilience-climate-change-vulnera...
Raw data set https://www.dcbd.nl/document/household-resilience-climate-change-vulnera...

Part of the larger The impacts of climate change on Bonaire (2022-present) report available here.
 

Summary

Climate change is the biggest “global health threat facing humanity” in the 21st century. Climate change will very likely affect public health on Caribbean small islands, as small island developing states are highly vulnerable to the climate change impacts on health. Currently, small island developing states already “carry heavy burdens” in the form of non-communicable diseases, malnutrition, and obesity. The Caribbean region is especially vulnerable to the impacts of climate change and this project investigates the impacts of climate change on Bonaire’s public health situation.  

The effects of climate change on various aspects of Bonairians’ health conditions are determined by focussing on the impacts on vector-borne diseases, non-communicable diseases, and mental health, among others. In order to explore the current health situation on Bonaire and the possible impacts on public health associated with climate change, desk research is combined with expert interviews.

Although climate change induced floods can result in increased injury and accidental mortality (WHO, 2021), such physical trauma only makes up a minor part of the health climate change impacts. In reality, many more impacts can be seen in terms of vectorborne diseases, non-communicable diseases, mental health, and other health problems. The results indicate that Bonaire’s public health is vulnerable to climate change affecting vector-borne diseases, malnutrition and food insecurity, noncommunicable diseases, heat-related stress and mortality, and mental health issues, among others. Decision-makers should take their responsibility to support Bonaire’s adaptation to the expected impacts accordingly. 

Part of the larger The impacts of climate change on Bonaire (2022-present) report available here.
 

Summary

Climate change causes many problems, including non-economic loss and damage. However, non-economic damages are often overlooked as they are hard to measure and not felt by the wider society. The Caribbean region is especially vulnerable to the impacts of climate change. This project investigates the impacts of climate change on cultural heritage on Bonaire.

Expert interviews, participatory mapping, and social media analysis were applied to identify Bonaire’s most important cultural heritage. Overlaying the resulting cultural heritage maps with inundation and flood maps from the different climate change scenarios for 2150 showed the predicted impacts of climate change on tangible cultural heritage. The inundation maps show that the southern tip of the island, with its lighthouse, slave huts, and salt pans, will most likely be flooded in 2150, as well parts of Kralendijk under climate scenarios SSP5-8.5 and SSP5-8.5 LC. The climate change impacts on intangible cultural heritage was predicted by means of expert interviews. Climate change is predicted to impact fisheries, agricultural practices, art, and festivities on Bonaire, even though these results are more exploratory and uncertain. Bonaire’s cultural heritage is at risk and the island will be disproportionately affected by climate change. Decision-makers should take their responsibility to support Bonaire’s adaptation to the expected impacts accordingly.