Lac Bay

1.Background

The queen conch, orLobatus gigas, is an iconic species found within the Caribbean, beingboth economically andsocially important.Famous for its unique and beautiful shell, alongwith its role as a popular item in local dishes, this species is heavily fishedand, in someareas,highly threatened.A project started in the 1980's, Marcultura, worked to boost localpopulations by cultivating conch to be released in the bay (Hensen,1983). Unfortunately,there were no long-term positive impacts to the conch populations after this project.Since November 1992, queen conch havebeen listed as an CITES Appendix II species,which means it is at risk of endangerment. However, due to concerns over local populations,taking conch from Bonaire has been forbidden since 1985. Only legal imports (from countrieswith CITES export permits) are allowed. Unfortunately, poaching is still an ongoing issue forthe island.The conch middens (old shells) that can be seen in large piles along the Lac Caibeach are from conch caught locally and brought in from the Aves Islands.Other species in the genusLobatusandStrombusareLobatus raninus (hawkwing conch),Lobatus costatus(milk conch) andStrombus pugilus (fighting conch) also occur on Bonaire.Lobatus costatusare taken incidentally but their shell is verythick,and they have very littlemeat.

Nederlands below.

The mangrove forest of Lac Bay, Bonaire, is experiencing a die-off of trees in its northern area. Increasing the tidal exchange by creek restoration likely increases the living conditions for the mangrove trees. In the first months of 2022, a collaboration between the Mangrove Maniacs and the University of Twente was set up to investigate the hydrodynamic properties of the area and looked into the effects of creek restoration.

Creek in Lac Bay opened by the Mangrove Maniacs. Photo source: Rob van Zee

Lac Bay

Mangrove systems worldwide promote ecological diversity while also being economically valuable for humanity. If a mangrove forest experiences die-back, it loses the services it provides. One such case is the mangrove forest of Lac Bay, Bonaire. The northern side of Lac Bay, also known as Awa di Lodo, is experiencing a die-back of mangroves. Unsustainable overgrazing by livestock on Bonaire has depleted the area of ground cover vegetation resulting in the wind, vehicle traffic, and rainwater mobilizing and transporting sediment into Awa di Lodo. The excess sediment in combination with growing mangrove roots clogs lagoons and creeks, eventually closing off these creeks, reducing the hydrological connectivity between the front and back of the forest. High evaporation rates and a low influx of freshwater create hypersaline conditions in Awa di Lodo. The Mangrove Maniacs are trying to open the mangrove creeks so the tidal exchange (the tide-induced volume of water reaching Awa di Lodo) increases, lowering the salinity values in the area. However, it is yet unclear to what extent the existing creeks contribute to the tidal exchange in Lac Bay and to what extent creek restoration can improve the tidal exchange in Lac Bay.

Research

At the start of the year 2022, a group of researchers from the University of Twente monitored water levels and velocities and mapped topographic characteristics of Lac Bay. One of the goals was to create insight into the hydrodynamics of the mangrove system through in-depth analysis of this data. The propagation of the tidal wave, relations between the water levels and velocities and the tidal asymmetry were investigated. Next, a numerical model was developed to quantify the influence of creeks on the tidal exchange and to investigate the effect of creek restoration on the tidal exchange. To quantify the tidal exchange, the residence time of the water in Awa di Lodo was computed, which is the time it takes (in days) for the tidal exchange to completely replace the total water volume of Awa di Lodo.

Results

The obtained data shows that the diurnal tidal wave has a negligible delay in the open water of Lac Bay. In Awa di Lodo, high water is reached on average more than four hours later than in the open bay. During spring tides, the tidal range in the open water is sufficiently large to create an increasing trend in the water level in Awa di Lodo. The water level in Awa di Lodo lowers again when the tidal range decreases during consecutive neap tides. Flow velocities in the creeks mainly depended on the water level difference between the open water and Awa di Lodo. Both ebb- and flood-dominant peak velocity asymmetries are observed in the creeks. The observed flood-dominant tidal duration asymmetry in Awa di Lodo indicates that sheet flow during high tides is responsible for the fast increase of the water level in Awa di Lodo while during low tides the creeks are responsible for the outflow.

The hydrodynamic model showed that creeks significantly influence the tidal exchange from the open water in Lac Bay to Awa di Lodo (Table 1). A new creek connection to Awa di Lodo, preferably by extension of the creek through the center of the mangrove system, is found to be the most efficient to increase the tidal exchange. It was also concluded that the widening of the creeks, deepening of the creeks or the extension of the eastern creek system would have a limited effect on the tidal exchange. Hence creek restoration is shown to be an effective measure to increase the tidal exchange in the mangrove forest of Lac Bay.

Table 1: Tidal exchange, residence time and the ratio of the residence time of any of the scenarios compared to the reference scenario. Red coloured rows indicate a decrease in tidal exchange and blue coloured rows indicate an increase in tidal exchange. A darker shade implies a greater decrease/increase

Impacts on the future

The data analysis and the developed hydrodynamic model will be important tools for the Mangrove Maniacs to make decisions on where to open new creeks and to study the impact of their work. By having more insight into the hydrodynamics of Lac Bay, the mangrove restoration will become more effective and thus increase the ecological value of the area.

For more information, you can read the full report using the DCBD link below.

More info in the Dutch Caribbean Biodiversity Database

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De invloed van kreken op de getijdenuitwisseling in het mangrovebos van Lac Bay, Bonaire

Het mangrovebos van Lac Bay, Bonaire, ervaart het afsterven van bomen in het noordelijke gebied. Er is een goede kans dat het verhogen van de getijdenuitwisseling door het herstellen van mangrove kreken de leefomstandigheden van de bomen verbeterd. In de eerste maanden van 2022 is een samenwerking opgezet tussen de Mangrove Maniacs en de Universiteit Twente om de hydrodynamische eigenschappen van het gebied en de effecten van kreekherstel te onderzoeken.

Kreek in Lac Bay die geopend is door de Mangrove Maniacs. Photo source: Rob van Zee

Lac Bay

Wereldwijd bevorderen mangrovesystemen ecologische diversiteit terwijl ze ook van economische waarde zijn voor de mensheid. Als een mangrovebos sterft, verliest het een voor een groot deel de waarde die het kan toevoegen aan de wereld. Een voorbeeld hiervan is het mangrovebos van Lac Bay, Bonaire. Het gebied aan de noordkant van Lac Bay, ook wel bekend als Awa di Lodo, ervaart het afsterven van mangroven. Niet-duurzame overbegrazing door vee op Bonaire heeft het gebied ontdaan van bodem bedekkende vegetatie, waardoor wind, autoverkeer en regenwater de kans hebben om sediment naar Awa di Lodo te transporteren. Overtollig sediment in combinatie met de groeiende mangrovewortels verstoppen de lagunes en kreken waardoor deze uiteindelijk dicht komen te zitten. Hierdoor wordt de hydrologische connectiviteit tussen de voor- en achterkant van het bos wordt verminderd. Hoge verdampingswaarden en een lage instroom van zoet water creëren extreem zoute omstandigheden in Awa di Lodo. De Mangrove Maniacs proberen de  mangrove kreken te openen zodat de getijdenuitwisseling (het volume water dat door het getij Awa di Lodo bereikt) toeneemt, waardoor het zoutgehalte in het gebied daalt. Het is echter nog onduidelijk in hoeverre de bestaande kreken bijdragen aan de getijdenuitwisseling in Lac Bay en in hoeverre kreekherstel de getijdenuitwisseling in Lac Bay kan verbeteren.

Onderzoek

Begin 2022 heeft een groep onderzoekers van de Universiteit Twente de waterstanden en snelheden gemeten en topografische kenmerken van Lac Bay in kaart gebracht. Een van de doelen een diepgaande data-analyse om inzicht te krijgen in de hydrodynamica van het mangrovesysteem. Er is gekeken naar de voortplanting van de vloedgolf, relaties tussen de waterstanden en watersnelheden en naar de getijdenasymmetrie. Vervolgens werd een numeriek model ontwikkeld om de invloed van kreken op de getijdenuitwisseling te kwantificeren en om het effect van kreekherstel op de getijdenuitwisseling te onderzoeken. Om de getijwisseling te kwantificeren is de verblijftijd van het water in Awa di Lodo berekend, dat de tijd die nodig is (in dagen) voordat de getijwisseling het totale watervolume van Awa di Lodo volledig heeft vervangen.

Resultaten

Uit de verkregen data blijkt dat de dagelijkse vloedgolf een verwaarloosbare vertraging heeft in het open water van Lac Bay. In Awa di Lodo wordt het hoogwater gemiddeld meer dan vier uur later bereikt dan in de open baai. Tijdens springtij is het getijverschil in het open water groot genoeg om een ​​stijgende trend in het waterpeil in Awa di Lodo te creëren. Het waterpeil in Awa di Lodo daalt weer wanneer het getijverschil afneemt bij opeenvolgende doodtij. Stroomsnelheden in de kreken zijn vooral afhankelijk van het waterpeilverschil tussen het open water en Awa di Lodo. In de kreken worden zowel eb- als vloed-dominante pieksnelheidsasymmetrieën waargenomen. De waargenomen vloed-dominante asymmetrie in de getijdenduur in Awa di Lodo geeft aan dat de stroming tussen de mangrovebomen door tijdens hoogwater verantwoordelijk is voor de snelle stijging van het waterpeil in Awa di Lodo. Tijdens eb zijn juist de kreken verantwoordelijk voor de uitstroom en de daling van het waterpeil in Awa di Lodo.

Het hydrodynamische model toonde aan dat kreken een significante invloed hebben op de getijdenuitwisseling van het open water in Lac Bay naar Awa di Lodo (Tabel 1). Een nieuwe kreekverbinding met Awa di Lodo, ​​bij voorkeur door verlenging van de kreek door het midden van het mangrovesysteem, blijkt het meest efficiënt te zijn om de getijdenuitwisseling te vergroten. Ook werd geconcludeerd dat de verbreding van de kreken, de verdieping van de kreken of de uitbreiding van het oostelijke krekenstelsel een beperkt effect op de getijdenuitwisseling zou hebben. Daarom is aangetoond dat kreekherstel een effectieve maatregel is om de getijdenuitwisseling in het mangrovebos van Lac Bay te vergroten.

Tabel 1: Getijdenuitwisseling, verblijftijd en de verhouding van de verblijftijd van elk van de scenario’s ten opzichte van het referentiescenario. Roodgekleurde rijen duiden op een afname van de getijwisseling en blauwgekleurde rijen duiden op een toename van de getijwisseling. Een donkerdere tint impliceert een grotere afname/toename

Impact op de toekomst

De data-analyse en het ontwikkelde hydrodynamische model zullen belangrijke instrumenten zijn voor de Mangrove Maniacs om beslissingen te nemen over waar nieuwe kreken te openen en om de impact van hun werk te bestuderen. Door meer inzicht te krijgen in de hydrodynamica van Lac Bay zal het herstel van het mangrovebos effectiever worden en zal daarmee de ecologische waarde van het gebied vergroten.

More info in the Dutch Caribbean Biodiversity Database

Published in BioNews 57.

Abstract

The mangrove forest in Lac Bay, Bonaire, experiences a die-off of trees in its northern area (Awa di Lodo). This die-off is caused by a combination of hypersaline conditions, long inundation periods and excess sedimentation. It is expected that an increase in the tidal exchange between Lac Bay and Awa di Lodo will decrease the mangrove stressors in Awa di Lodo creating improved environmental conditions for mangroves to grow. The tidal exchange consists of flow through the vegetated forest (sheet flow) and through the creeks (creek flow). Awa di Lodo has two main creeks connections to the forest fringe, the eastern and the western creek system. Due to mangrove roots growing into the creeks in combination with sedimentation, the creeks eventually close off and thereby reduce the creek flow. The Mangrove Maniacs are restoring the creeks in Lac Bay to improve environmental conditions for mangroves and they want a better understanding of the impacts of their work. This study aims to create more insight into the tidal-induced hydrodynamic processes in Lac Bay and the contribution of creeks in the mangrove forest to the tidal exchange.

During a field campaign from January to March 2022 field data were collected on flow velocities, water levels and topographic characteristics of Lac Bay. The field campaign spanned three spring-neap tidal cycles. The analysis of the gathered data was combined with a literature study to investigate the hydrodynamic characteristics in the area. Based on the data from the field campaign, a hydrodynamic model (Delft3D) was built to analyse the effects of tidal creeks restoration on flow velocities, tidal exchange and water levels of Awa di Lodo.

The field measurements show that the tidal wave is diurnal and has a negligible delay propagating through the open water of Lac Bay. In Awa di Lodo, high water is reached on average more than four hours later than in the open bay. During spring tide, the tidal range in the open water is sufficiently large to create an increasing trend in the water level in Awa di Lodo. The water level lowers again when the tidal range decreases during neap tide. Flow velocities in the creeks mainly depend on the water level difference between the open water and Awa di Lodo, meaning that larger water level differences induce larger flow velocities. In addition, the western creek connecting the bay with Awa di Lodo shows a strong flood dominant peak velocity asymmetry, while the eastern creek varies from marginally flood dominant during spring tides, to strongly ebb dominant during neap tide. A flood dominant tidal duration asymmetry in Awa di Lodo indicates that sheet flow during high tides is responsible for the fast increase of the water level in Awa di Lodo while during low tides the creeks are responsible for the outflow.

The hydrodynamic model simulations of the tidal dynamics in Lac Bay replicate the magnitude of the measured flow velocities in the creeks of Lac Bay. The model does not show the measured ebb flow in the western and centre creek. Water levels in Awa di Lodo are modelled well, except for an overestimation of low water levels and an overestimation of the water level increase. It was found that creeks have a significant influence on the tidal exchange between the open water and Lac Bay. The model showed that the creation of a new creek connection to Awa di Lodo, either by extending the centre creek or by creating a new creek, is found to be the most efficient to increase the tidal exchange. It was concluded that the widening of the creeks, deepening of the creeks or extension of the eastern creek system would have a limited effect on the tidal exchange. Creek restoration is shown to be an effective measure to increase the tidal exchange in the mangrove forest of Lac Bay.

In Lac Bay, Bonaire, a part of the mangrove forest is dying partly because of reduced water circulation through the forest. Tidal waves are the main drivers of the water circulation in the forest. In this study, the tidal behaviour is analysed based on water depth measurements from earlier studies in 2012 in Lac Bay. Time series are used to determine the tidal range (difference between minimum and maximum water depth), the dominant tidal constituent (harmonic analysis) and the water circulation through the forest (difference between the timing of highest water depth). The results show that locations close to open water in the bay have on average a large tidal range (27.8-28.1 cm) than locations in the forest (3.4-8.1 cm), with limited to no seasonal fluctuations. The dominant tide in Lac Bay is the lunisolar diurnal constituent (K1). Water depth changes from stations close to open water could be explained reasonably but in other locations they were distorted by the forest and could not be fully explained. It was found that the water moves slowly through the forest in a circular manner, moving around the islands and through the forest, thereby creating a delay in high water depths up to five-and-a-half hours.

Key words: Mangroves; Lac Bay; Water depths; Tidal range; Dominant tide; Tidal constituents

Lac Bay is the lagoon of Bonaire; in that lagoon a mangrove forest of red and black mangroves grows. The mangrove forest of Lac provides birds and fishes of the surrounding
area with several important ecosystem services, as breeding ground, nursery and feeding area. These eco-­‐services are threatened by a reduced water circulation which causes low
water heights in the backlands and thus a reduction of the area which is available to fishes. Water in the backland was measured hypersaline, the obtained result of low water circulation and high evaporation in the backlands.

This hypersaline values may reduce the area of viable mangroves in the backlands. The lagoon and the backlands are connected  through two feeder channels and those natural channels will overgrow when no maintenance is applied causing even less water flowing into the backlands. Calculating appropriate channel dimensions and formulating a maintenance plan a certain discharge into the backlands can be ensured, which may reduce the degradation of ecosystem services.

Map of Mangrove Populations of Lac Bay

Erdmann, W., Scheffers, A. 2006. Mangrove Population of Lac (Bonaire) 1961 and 1996,  Universität Duisburg-Essen - Institut für Geographie 

Executive Summary

This Site Characterization report provides a comprehensive coverage of past and present scientific research that had been conducted and recorded in Lac Bay during the 20th Century. Elements of environmental change are evaluated in this writing by comparing information from the prior studies, and drawing implications from them against recent data collected from a year long ecological monitoring series that were conducted throughout 1999 by Environics, N.V. Consulting.

Additional implications were based on ground-truthing a series of aerial photographs that were completed over the years. The consultant activities were proposed to the Bonaire Marine Park and VOMIL to respond to the management needs listed in the Bonaire Marine Park Terms of Reference LAC001/98, by investigating the following research questions:
• What is the current health and status of the bay area and surrounding environs, and how has it changed from the past to present, as determined through the interpretation of aerial
photographs, scientific research and local historical knowledge?
• What is the status of the globally endangered species, the queen conch (Strombus gigas), which inhabit Lac Bay?
• How is the bay currently being used by marine life, wildlife, and by humans?
• Are there indications of threats on the bay’s natural carrying capacity?

These would begin to provide relevant data in which to support decisions pursuant to the associated public concern issues of the following that are addressed in Section 9 of this report:
• Opening channels to “refresh” the dying mangrove wetlands;
• Extracting sand materials from the Sorobon site; and
• Fisheries exploitation of the queen conch.

The following key environmental problems were found in the research:
• Conch Population Decline Field monitoring activities determined that the conch population size class distribution of a 51,000-m2 area found approximately 111 conch individuals, with an average age of 2.5 years old. No
adult conchs were found in Lac Bay. In brief, the statistical results indicate that for both conch and invertebrate species in general, the spatial distribution patterns for conch locations in the bay, are found to
be in clumps, implying potential constraints on the population. For conch, fishing pressure may be likely, as the mapping results show the remnant conch population is located in the deeper bay channel or boat
routes, where the species have least potential accessibility by people fishing for conch. Evidence of juvenile conch species being fished out before reaching adult reproduction size can also be found in the
discarded conch piles at Cai, re-enforcing the field data that no adult conch exist in Lac. Taking juveniles may contribute to the extinction of conch in Lac Bay.

• Mangrove Die-off and Hydrology
Hydrological monitoring in the mangrove sub-basin areas found that annual salinities ranged from 44 0/00 to 180 0/00 throughout the area (normal bay salinity averages 44 0/00 ). Two main feeder channels
that circulate bay water from the Lac lagoon, into the mangrove sub-basin areas occur in the Kreek di Pedro and Kreek di Coco areas. A third, less regular tide water delivery channel occurs across the Isla di
Chico during high water events. Annual tidal flooding and draining phenomena occur during the March and September solstice periods that influences the environmental conditions in the mangroves wetlands.
During the March solstice, the tidal waters drain rapidly, depleting the oxygen balance in the natural system, and fish kills frequently occur during this annual event. This dynamic process is part of a natural
annual cycle that is typical for the mangrove environment at Lac.

Fresh water flow has been altered over history by building levees, such as at Mona Lisa levee, as well as ill-designed road construction and failing culverts. Periodic fresh water flow into the mangroves is a part of the natural system that provides balance for mangrove viability; it has been grossly altered at the mangrove sub-basin areas, and no longer functions.

• Sedimentation Processes in Lac
Sedimentation processes occur due to deposition of sands that are carried in from currents crossing over the coral “dam” that naturally separates the Lac from the coastal oceans. Sedimentation creates the
Awa Blanku area. The circulatory patterns in the bay move in a clockwise pattern, that also diverge into the feeder channels that provide water into the mangrove sub-basin areas of the north, depositing sand in
the process. In addition, sedimentation occurs in an ephemeral time scale in the area behind the Isla di Pedro. Historical interpretation of maps since the 1961 aerials, show sand deposition in 1961, no sand deposition in 1991, but sand deposition again in 1998 aerials. This again appears to be a natural cycle of the ecosystem rhythm, which occurs in Lac.

• Management Recommendations
After analyzing the GIS mapping results for seagrass habitat abundance, etc., a zonation plan of the bay is recommended to demarcate a sanctuary preservation area to replenish for viable conch and other wildlife habitats, as well as to designate multi-purpose recreational use areas. The map products include a GIS zonation map of the natural communities of Lac Bay in Section 3, with management recommendations for the greater bay area found in Section 10.

An example of a recommended zonation plan is found in Section 10. Thereafter, a fisheries management program could be implemented, enforced through issuance of permits and size class catch
limits is recommended, that would sustain conch population and commercial fisheries, as well as for local family consumption. Outside mangrove, shoreline restoration experts, as well as a hydrology engineer were invited to examine the “environmental” problems at Lac, and provide management recommendations in Section 9.

The conclusions of environmental symptoms, stressors and biological responses to stress that were identified through scientific research are contained in the final Section 10. In addition, community
stakeholders who are concerned for Lac met a consensus on how best to manage Lac; the comprehensive evaluation is provided in Section 10.

The following is a summary list of final management recommendations, as identified by scientific experts and community stakeholders for Lac Bay:
• Permit local, artesinal fishing practices in Lac only with catch quantity and size limits strictly enforced
• Issue permits to control fishing, netting or taking conch
• Initiate a 5-year moratorium against taking conch, and monitor every 3 years for size class distribution for the species in Lac Bay
• Enforce strict size limits of conch to protect taking of juveniles
• Enforce existing legislation to ban taking turtles, protect eggs and nests
• Legally exclude non-Bonaire registered boats to use Lac Bay waters
• Strictly prohibit sand extracting in Lac
• Support water quality standards at Cai
• DROB upgrade Cai road culverts to improve water circulation capabilities
• Disallow cutting of mangroves
• Monitor water quality standards at established sites around bay area
• Sorobon Beach Resort erosion can be safeguarded by removal of lower sections of the groin fence that are below the mean high water line that would greatly help the beaches to the north, without compromising privacy.
• Control car traffic and parking along beach strand of Cai; park outside of Cai area on hard limestone surface
• Establish an environmental education kiosk system throughout the Lac area to explain environmental processes, problems and solutions to promote community self-management and self-regulation.

Ecological status of Lac Bay, Bonaire

Client: Departement voor Ontwikkelingssamenwerking Nederlandse Antillen (DEPOS)

Project nr: 90.04

For more information, contact Bureau Waardenburg BV https://www.buwa.nl/en/contact.html

Historical map of Lac with papiamento names.

Chronic stressors such as water pollution, overfishing, and ocean warming are major threats to the resilience of coral reefs as they influence processes that underlie resistance and recovery of reef ecosystems. Local management actions and policy increasingly have to focus on supporting the resilience of these ecosystems. This requires customization of management on smaller spatial scales.

Tourism contributes to reduced water quality due to the emission of suncare products by swimming recreationists. Recent research shows that UV filters (viz. oxybenzone) in suncare products can contribute to reduced vitality of coral ecosystems. Monitoring in 2016 showed that these substances are also present in coastal waters of Bonaire, at levels of serious environmental concern.

Although water quality of Bonaire seems to be affected by sunscreen pollution, the local action perspective is also specific. The public opinion can be influenced by translating scientific results to articles suitable for a broader public audience and by providing accessible information via various media. Raising public awareness may result in both reduced supply and use of specific harmful products, since appropriate alternatives are already available.

WWF and the Ministry of Economic affairs assigned various smaller projects of which the activities, results and conclusions are presented in this report. WMR and Boneiru Duraderu worked together on these assignments in the so called “Sunscreen awareness project”.

Main research questions were:

• Was the presence of polluting UV filters at Sorobon in 2016 a one-time observation, or are these substances found in other time periods as well. Do concentrations depend on tourism intensity and products used?
• How can the local use of sunscreen products containing oxybenzone be effectively influenced, so that coral ecosystems on Bonaire are no longer at risk from such products.

To answer these question various activities were exploited:

• Monitoring and surveys:

• Chemical monitoring with focus on field concentrations of UV filters in November 2017 during the peak of the cruise season.
• Conducting Beach surveys among tourists in order get preliminary information on tourist intensity and sunscreen use during field monitoring.

• Stakeholder involvement:

• Conduct shop surveys in order to get information on products sold and willingness of owners to make a change.
• Host a conference to present results and to prepare a voluntary covenant and involve stakeholders.
• Contribute with scientific knowledge to media and local provide information.

Monitoring of UV filter levels showed that UV filters oxybezone and octocrylene were present in the water, at levels indicating environmental risk. Risk quotients (RQ) of oxybenzone range between 0 and 2.8 whereas risk quotients of octocrylene range between 6 and 52. It should however be noted that the RQ’s of octocrylene are derived from a rather limited data set, and are higher due to the higher uncertainty factor applied.

Although the study was indicative, UV-filter levels and thus risk seem to be related to tourist intensity, origin and product use. Levels of especially oxybenzone were higher when more oxybenzone products were used among tourists on the beach. These tourists originated mostly from the US, enjoying a cruise holiday. Stay-over tourists from the EU show a relatively limited use of oxybenzone-based sunscreen products.

Stakeholder involvement included surveys and interviews in the preparation towards the Sunscreen Awareness conference at which various stakeholder were invited to discuss how to move forward on the topic.

The attendees of the conference participated in a lively discussion, and the following paths forward were identified:

1. Legal Ban for sunscreens.
2. Changing consumer behaviour.
3. Introduction of an environmental tax for cruise tourist.

Stakeholders vary in their view towards the daily practice and effectivity of a legal ban, and pro’s and con’s are listed in the report. Common ground was found in the possibility to include a rule in the Marine Park management plan to strengthen the communication about the subject. Awareness and influencing consumer behaviour was viewed as the best way to move forward. Moreover, an awareness campaign can be implemented much faster than a law. To pay for such an ongoing awareness campaign, the introduction of an environmental tax for cruise tourists was suggested. Remarks and additional research questions are listed in the report.

In summary, future research and awareness should focus on:

• additional monitoring at the west coast to broaden the scope and relation to tourist origin, density and product use
• effects of field relevant levels of sunscreen
• study the effect of so called “safe alternatives”
• involvement of the cruise sector, and study the willingness to change to other products