Environ Biol Fish https://doi.org/10.1007/s10641-018-0811-6 A baseline analysis of coastal water quality of the port Honduras marine reserve, Belize: a critical habitat for sport fisheries Brenna M. Sweetman & James R. Foley & Michael K. Steinberg Received: 16 January 2018 /Accepted: 21 August 2018 # Springer Nature B.V. 2018 Abstract This analysis examines temporal changes in and low population density of southern Belize. This water quality of the Port Honduras Marine Reserve study provides baseline information for future research (PHMR), Belize from 1998 to 2015. Trends in dissolved and outlines recommendations for management strate- oxygen (DO), salinity, temperature and pH were ana- gies of PHMR to mitigate impacts from current and lyzed from ten sites throughout PHMR for statistically future threats to water quality. significant relationships. Maintaining satisfactory water quality is critical for sustaining healthy fisheries. PHMR Keywords Water quality . Fish habitat . Belize . Sport represents a unique link between upland watersheds and fishing . Marine reserve coastal wetlands, mangroves, coral reefs, and seagrass beds. These ecosystems comprise important habitat for many fisheries including the economically valuable Introduction sport fish species of Megalops atlanticus (Atlantic tar- pon),Albulavulpes(bonefish) and Trachinotus falcatus Marine and coastal ecosystems are considered some of (permit). Sport fishing in the PHMR area has become the most biodiverse and highly vulnerable ecosystems increasingly popular in recent decades and is responsi- globally (Gray 1997;Wormetal.2006; Bierman et al. ble for generating direct and indirect income opportuni- 2011). Marine protected areas (MPAs), such as the Port ties for local communities, including Punta Gorda, the Honduras Marine Reserve (PHMR) in southern Belize, largest town in southern Belize. As a result, degradation are commonly used to maintain marine biological diver- of water quality of PHMR through land-based human sity and protect ecosystem health by monitoring and activities could have ecological and economic conse- regulating human activities (Kelleher and Kenchington quences for southern Belize. The results of the analyses 1991;Jones1994). These efforts in turn support the revealed significant seasonal variations and slight in- sustainable utilization of natural resources through eco- creasing trends in DO and salinity at several sampling tourism activities such as sport fishing (Di Lorenzo et al. sites. These relatively stable results are likely related to 2016). several factors including limited coastal development Water quality is the foundation of healthy marine habitat for fisheries. Degradation of water quality, hab- itat degradation, or a combination of both, can have B. M. Sweetman (*) : M. K. Steinberg Department of Geography, University of Alabama, Tuscaloosa, cascading consequences for fisheries and associated AL 35487, USA ecosystems (Karr 1981). Traditionally, water quality e-mail: [email protected] has been defined as the physical and chemical constitu- J. R. Foley ents of water required for human or ecosystem needs The Nature Conservancy, Belmopan, Belize (Karr and Dudley 1981). To maintain reproductive rates Environ Biol Fish and competitive abilities, fish species require specific atlanticus) and permit (Trachinotus falcatus) (Beck water quality standards, with deviation from normal et al. 2001; Gilliers et al. 2004; Adams and Cooke ranges resulting in adverse ecological impacts and de- 2015). Sport fishing for permit, bonefish and tarpon in clining populations (Jobling 1981; Karr and Dudley PHMR is considered a major component of the ecotour- 1981). For example, the depletion of DO influences ism industry in southern Belize, generating more than metabolic activity (Kramer 1987); salinity, a variable US$695,000 nationally in 2005 (Coleman and Diamond highly influenced by freshwater influx and precipitation, 2005). The lagoons and adjacent patch reefs of PHMR is critical for growth and reproduction; (Montague and provide the focal destination for permit sportfishing Ley 1993) and temperature is closely linked to biolog- guides in Belize and many view PHMR as the most ical productivity (Brett 1969; Houde 1989). Marine important permit fishing grounds in all southern Belize. water quality is complex and these variables can be In fact, Punta Gorda has dubbed itself the Bpermit influenced by both natural and anthropogenic processes capital^ of Belize. In the Toledo District, and elsewhere (Karydis and Kitsiou 2013; Krembs and Sackmann in the country, guiding for sport fish is considered one of 2015). the most desirable jobs and is passed down from gener- Upland land-use change is one variable that can ation to generation. These activities produce significant accelerate changes in coastal water quality (Meador economic benefits through direct and indirect expendi- and Goldstein 2003; Foley et al. 2005). For PHMR, tures to the local communities. Robinson et al. estimated threats to water quality have been identified as that PHMR generates annual revenues of approximately watershed-based pollution, nutrient fertilizer runoff US$2.41 million based on fisheries, tourism and recre- and erosion from the adjacent watersheds that discharge ation values, highlighting the strong economic value of to the coastal waters (Heyman and Kjerfve 1999;Foley PHMR (Robinson et al. 2004). et al. 2015). In addition to understanding impacts from Although other studies have examined water quality land-use change, examining indirect anthropogenic in- of the PHMR region in the past (Sullivan et al. 1995; fluences on water resources from climate change is an Heyman and Kjerfve 1999), no studies have evaluated issue of global concern (Vörösmarty et al. 2000). long-term changes since the establishment of PHMR as Geospatial modeling scenarios for 2020 to 2080 for an MPA in 2000. Water quality data for a 17-year period Central America indicate the possibility of higher tem- is a valuable and impressive quantity of data for a peratures for Belize as well as reduced precipitation tropical, developing country. Additionally, scientific rates, potentially perturbing water temperature and sa- habitat studies are lacking for flats fisheries, with recent linity of shallow tropical ecosystems (Anderson et al. research mostly concentrated in the Bahamas and the 2008). Long-term water quality data are therefore criti- U.S. rather than the Caribbean (Adams and Cooke cal to understand directional changes in water resources 2015). This study directly addresses this issue by focus- to enable resource managers to better regulate both sport ing on fisheries habitat and water quality in Belize, an and commercial fishing activities (Ahmadia et al. 2015). understudied area quickly becoming known as a world- MPAs serve critical ecological roles by protecting class fly fishing destination. The objectives of this study fish nurseries, managing fisheries and preserving habi- were to analyze the temporal trends of DO, salinity, tat, among others (Lauck et al. 1998;Becketal.2001; temperature and pH of the coastal waters of PHMR Blyth-Skyrme 2006). In addition to high ecological between 1998 and 2015 and gain a broad understanding value, MPAs also provide important economic value of human impacts on an ecologically complex and eco- by enhancing tourism and promoting sustainable devel- nomically important marine landscape for improved opment (Dixon et al. 1993;Cho2005). For Belize, 30% management and research efforts. of the nation’s gross domestic product is directly related to commercial ecotourism activities that occur in the coastal zone, with sport fishing highlighted as one of Methods the most economically lucrative (Cho 2005; Moreno 2005). Shallow coastal waters, such as those of PHMR, Study area are well known for providing habitat for juvenile and adult sport fish including the highly sought-after species The coastal portions of Belize are a component of the bonefish (Albula vulpes), Atlantic tarpon (Megalops wider tri-national area of the Gulf of Honduras. Within Environ Biol Fish the Gulf, PHMR is located between the latitudes 16° 08’ et al. 2003). Consequently, water quality is sensitive to Nand16° 12’ N and longitudes 88° 25’ Wand88° 45’ the watershed processes and land cover of the countries Won the coast of southern Belize and covers an area surrounding Belize. of 414 km2 (Fig. 1). East of PHMR is the southern During the wet season discharge typically exceeds extension of the Belize Barrier Reef Reserve system, the dry season discharge by a factor of 5–9(Heyman the second largest barrier reef in the world and a and Kjerfve 1999; Burke and Sugg 2006). High precip- renowned UNESCO World Heritage Site (UNESCO itation during the wet season contributes to significant 2017). Inland and west of PHMR is the Toledo Dis- runoff of sediment and freshwater which drive gravita- trict, the southernmost and least densely populated tional currents. A study estimated terrestrial runoff to the district of Belize. The Toledo District contains the Gulf of Honduras using river discharge and ocean cir- Maya Mountain Marine Corridor and the seven wa- culation models and showed that the Gulf undergoes tersheds that drain into PHMR: Deep River, Golden considerable seasonal influence of suspended sediments Stream, Middle River, Monkey River, Punta Ycacos and dissolved nutrients (Chérubin et al. 2008). The Lagoon, Rio Grande and Indian Hill Lagoon intense precipitation during wet season is one of the (Heyman