First observation of vervet monkeys Chlorocebus pygerythrus feeding on seagrass Thalassodendron ciliatum along the Tanzanian coast

The vervet monkey, Chlorocebus pygerythrus (F. Cuvier, 1821), is among the most abundant and widely distributed primates in eastern and southern Africa (Butynski et al., 2013). In Tanzania, it is found throughout most of the country, and in some places, forages in human settlement areas (Foley et al., 2014). Chlorocebus pygerythrus is an opportunistic omnivore, with flowers, leaves, seeds and invertebrates contributing a major part of its diet (Struhsaker, 1967; Wrangham & Waterman, 1981; Lee & Hauser, 1998; Butynski et al., 2013; Foley et al., 2014). Vervet monkeys are known to feed on terrestrial grasses e.g. Panicum spp, Sporobolus spp, Cynodon spp and Cenchrus mezianus (Leeke) Morrone (Struhsaker, 1967; Butynski et al., 2013), but there are no records of seagrasses as part of their diet. This note reports the first observation of C. pygerythrus feeding on the seagrass Thalassodendron ciliatum (Forssk.) Hartog (Cymodoceaceae) at Saadani National Park, on the shores of the Indian Ocean. Saadani National Park is one of 22 national parks in mainland Tanzania, and the only one bordering the Indian Ocean (TANAPA, 2020). It comprises the former Mkwaja ranch area, former Saadani game reserve and the Zaraninge forest (Treydte et al., 2005) and is located within the Zanzibar-Inhambane phytochorion (White, 1983). The mean annual temperature in the park is 25°C (Treydte et al., 2005) with the annual rainfall considerably variable between years (Tobler et al., 2003), generally averaging to 900 mm per annum (Treydte et al., 2005). Rainfall in the park is bimodal with a short rainy season from October to December and a long rainy season from March to early June (Treydte et al., 2005; Cochard & Edwards, 2011). Like most of the Western Indian Ocean, the hydrography of Saadani coast is shaped by northeast and southeast monsoon winds which occur between November to March and May to September respectively (Richmond, 2002; Lymo, 2011; Semba et al., 2019). The surface water temperature ranges from 20 to 30°C and is higher during northeast monsoon winds (Richmond, 2002; Lymo, 2011; Peter et al., 2018). At least 10 seagrass species are known along the Western Indian Ocean (Richmond, 2002; Gullström et al., 2002) with Thalassodendron ciliatum being among the most common (Gullström et al., 2002). A group of 22 vervet monkeys were observed on 31 August 2019 foraging along the shores of the Saadani National Park (6°01'42"S, 38°46'44"E ) for two hours from 10:00 h to 12:00 h during the low tide. The monkeys spent almost half of the time feeding on the terrestrial herbs Cynodon dactylon (L.) Pers., Sporobolus sp, Panicum sp and Anthericum sp on the supralittoral zone, before entering the littoral zone where they foraged on drift patches of the seagrass Thalassodendron ciliatum (figures 1 & 2). Identification of the seagrass followed Richmond (2002). The monkeys were observed eating rhizomes and shoots of T. ciliatum while avoiding the roots and leaves. Both direct mouth scrape and hand-to-mouth movements were used when the monkeys were feeding on the terrestrial grasses but only hand-to-mouth movements were used when feeding on T. ciliatum. A number of studies on non-human primates utilizing marine foods exist, in which marine animals dominate as food items (Son, 2003; Stewart et al., 2008; Lewis & O’Riain, 2017), especially invertebrates (Son, 2003).These reports indicate that marine resources contribute only small proportions of the primate’s food and that the animals invest little of their time on these feeding grounds (Lewis & O’Riain, 2017). However, detailed studies on feeding behaviour of vervet monkeys in Saadani National park will shed more light on feeding habits of  primates along the Tanzanian coast. This observation supports the opportunistic nature of vervet monkeys as  they are known to take advantage of available food resources (Struhsaker, 1967; Butynski et al., 2013). This is the first reported record of the seagrass T. ciliatum constituting a food item in the diet of vervet monkeys despite the occurrence of this seagrasses along parts of the distribution range of vervet monkeys

Structural complexity of seagrass and environmental variables as a determinant of fish larvae assemblages in tropical coastal waters: Implications for seagrass management and conservation

Anthropogenic activities including climate change affect the development of structural complexity in seagrass and the state of environmental variables. It remains unclear whether these variables, alone or in combination, have an important influence on fish larvae assemblages. This study examined the influence of the structural complexity of seagrass meadows and various environmental variables on fish larvae assemblages in tropical coastal waters of Tanga, Tanzania. The study was conducted in four Thalassia hemprichii dominated seagrass meadows from June 2019 to January 2021. Multiple regression analysis indicated that the structural complexity of seagrass (canopy height, seagrass cover, and shoot density) and environmental variables (dissolved oxygen, temperature and salinity) were the foremost predictors for fish larvae assemblages; abundance and richness (R2 = 0.75, p = 0.0185, R2 = 0.54, p = 0.0396, respectively). Based on these findings, the structural complexity of seagrass and environmental variables are both important determinants of fish larvae assemblages in tropical coastal waters. The findings suggest that reducing anthropogenic activities that affect the development of structural complexity of seagrass and negatively impact environmental variables in seagrass meadows through more effective governance would result in increased production of fish larvae in meadows and, as a result, increased fish recruitment in tropical coastal waters

Current State of Seagrasses in Zanzibar: Impacts of Coastal Economic Activities and Marine Protected Areas on Seagrass Cover

Seagrass meadows are located abundantly in Zanzibar, Tanzania and provide essential ecosystem services, such as sediment nutrient enrichment and blue carbon sequestration. However, seagrasses have been less researched or protected than other marine ecosystems. Although environmental variables affect seagrass health, evidence suggests that anthropogenic impacts are their greatest threats. The rapid expansion of seaweed farming and tourism and widespread use of harmful small-scale fishing practices in Zanzibar have contributed to the degradation and removal of seagrass meadows, disrupted coastal marine food chains, and reduced local biodiversity that seagrasses support. Public or private marine protected areas (MPAs) protect most of Zanzibar’s coastal marine ecosystems, yet evidence is unclear whether MPAs effectively conserve marine ecosystems. Using geographic information systems (GIS) to estimate the change in percent of seagrass cover from 2006 to 2019, we conducted Spearman’s rank correlation analyses to identify whether seagrass degradation was correlated with seaweed farming, fishing, or tourism and whether MPA management plans were protective. Tourism was negatively correlated with seagrass cover, r(9) = -0.74, p = 0.044, suggesting that tourism is an important driver of seagrass declines in Zanzibar. No other variables were significantly correlated with seagrass cover decline. To improve the management of seagrass meadows, plans must identify seagrasses as critical ecosystems, expand seagrass restoration projects, and address harmful practices in the tourism industry and other human impacts

Estructura poblacional del ‘pejepeine’, Xyrichtys novacula (Actinopterygii: Labridae), en mosaicos arena-pradera de fanerógama marina: variación espacial de acuerdo con las características del hábitat y técnicas de muestreo

Habitat structure affects the distribution of fishes, particularly across reef-dominated habitats, but few studies have connected patterns in the abundance of soft-bottom fishes with the structure of the habitat. The spatial and temporal patterns of variation in the abundance, biomass and population structure of the pearly razorfish, Xyrichtys novacula, inhabiting sand-Cymodocea nodosa seagrass mosaics were described through two complementary techniques: underwater visual counts and seine nets. We sought to analyse whether biotic (seagrass shoot density, leaf length and meadow cover) and abiotic (sediment composition and particle size) structural elements explained variation in patterns of abundance and biomass. Underwater visual counts registered a larger abundance of individuals and proved significant variation in fish abundance and biomass at the scale of locations, which was otherwise not detected through seine nets. Seasonal variation in fish abundance and biomass was, in all cases, minor. Habitat structural elements helped to explain patterns in fish abundance and biomass. This fish species was particularly abundant in sediments dominated by coarse sands in continuous meadows of C. nodosa ( > 90% seagrass cover) with intermediate densities of 500 to 1000 shoots m–2, followed by large-sized seagrass patches with >1000 shoots m–2. A trade-off between protection provided by seagrass canopies and protection derived from its burial behaviour, limited under high seagrass shoot densities, may explain spatial variation patterns.La estructura del hábitat afecta a la distribución de los peces, particularmente en los hábitats dominados por arrecifes. Sin embargo, los estudios que conectan patrones de abundancia de peces en fondos blandos con la estructura del hábitat son, comparativamente, más escasos. En este estudio, se describen los patrones espacio-temporales de variación en abundancia, biomasa y estructura poblacional del ‘pejepeine’, Xyrichtys novacula, en hábitats de arena y praderas de fanerógamas marinas constituidas por Cymodocea nodosa, empleando dos técnicas complementarias: censos visuales subacuáticos (UVCs) y arrastres (SNs). Se analizó si los elementos estructurales bióticos (densidad de pies, longitud de hoja y cobertura de la pradera) y abióticos (composición del sedimento y tamaño de las partículas) contribuyen a explicar la variación en los patrones de abundancia y biomasa. Los UVCs registraron una mayor abundancia de individuos y demostraron una variación significativa en abundancia y biomasa a escala de localidades, estas variaciones no fueron detectadas por los arrastres. La variación estacional en la abundancia y biomasa de individuos fue mínima en todos los casos. Los elementos estructurales del hábitat contribuyen a explicar los patrones de abundancia y biomasa de peces. Esta especie fue particularmente abundante en fondos dominados por arenas gruesas con praderas continuas de C. nodosa (cobertura > 90%) con densidades de pies intermedias de 500 1000 pies m–2. Un equilibrio entre la protección provista por la bóveda foliar y la protección derivada de su comportamiento de enterramiento, el cual está limitado por densidades de pies altas, puede explicar los patrones de variabilidad espacial de esta especie

Mediated Windows: The Use of Framing and Transparency in Designing for Presence

This paper explores the fusion of architecture and media technology that facilitates collaborative practices across spatial extensions: video-mediated spaces. The example presented is a mediated extension of the Museum of National Antiquities in Stockholm to a neighbouring park area and archaeological excavation site in 2008, referred to as a mediated window, or a glass-door. The concepts framing and transparency are used to outline the significance of windows and glazing in architecture and art. The author then considers the potential contribution of architecture in representing the passage from indoors to outdoors and designing for presence. Presence design assumes a contribution from architects to presence research, a currently diversified field, spanning media-space research, cognitive science, interaction design, ubiquitous computing, second-order cybernetics, and computer-supported collaborative work, but in which architecture and artistic practices are less represented. The paper thereby addresses the potential of an extended architectural practice, which incorporates the design of mediated spaces, and outlines presence design as a transdisciplinary practice in which presence research meets architectural design, and spatial and aesthetic conceptual tools, derived from related visual practices, may be productively applied

Temperate fish community variation over seasons in relation to large-scale geographic seascape variables

In shallow-water marine environments, ecosystem functioning is a complex interworking of fine-scale characteristics and region-wide factors, and the importance of these variables can vary on multiple temporal and spatial scales. This underwater video study targeted seasonal changes in the fish community of seagrass habitats along the Swedish west coast and the influence of offshore seascape variables (latitudinal position, wave exposure, open ocean, and deep water). Results showed that fish assemblage structure exhibited seasonal changes between summer and autumn and strong spatiotemporal variations in the importance of offshore factors affecting shallow-water fish communities. In summer, abundance from the Gobiidae family responded to wave exposure, whereas the Gadidae family and juvenile migrant habitat preference guild responded to latitudinal position and proximity to deep water. In autumn, deep water was related to abundance of Gadidae and juvenile migrants, whereas latitudinal position influenced Gasterosteidae. These findings underscore the importance of understanding the influence of offshore factors on facets of coastal fish assemblages to address large-scale geographic connectivity along nearshore– offshore gradients

Seagrass Beds Distribution and Their Structure in the Surrounding Coastal Waters of Kapoposang Island, South Sulawesi

Kapoposang Island and the surrounding waters has been appointed by Indonesian Governmet to be a part of waters tour park in South Sulawesi, implying the requirement of the marine resources, including seagrass ecosystems in this area, should be well managed in order to provide biodiversity protection and sustainable use of the seagrass ecosystems. For this purpose, one of basic required information is seagrass distribution and habitat structure. This study was aimed to 1) observe the location of continues seagrass beds, 2) identify the habitat structure in each site of continues seagrass beds. A combination of visual observation and transect method was applied to determine the sites of continues seagrass beds, while seagrass habitat structure was identified based on ecological habitat structure model. Study results revealed that continues seagrass beds were only found in five different sites of Kapoposang coastal waters. Seagrass habitat structure among the five sites were in variable and the highest seagrass cover was found in two sites, namely 1) site A in the north-west part of the island (S04o41'42.5"; E118o56'59.5") dominated by Thalassia hemprichii and 2) site E located in the north part of the island (S04o41'57.8"; E118o57'45.7") dominated by Enhalus acoroides. Both of these sites were different in heterogeneity but similar in complexity

Taking stock of mangrove and seagrass blue carbon ecosystems: A perspective for future carbon trading

Seagrass and mangroves support a number of ecosystem services, such as sustaining marine fisheries, water clarity, and the protection of shoreline from erosion. Producing a national and global consensus of their total worth is a challenge. More often than not the variety and distal evaluation approaches do not fit comfortably within current market-based economic models, which are arguably more capable of swaying government policy in assessing their preservation over economic development. The exception to this rule is the increasing recognition of the importance of these systems as a carbon sink for combating ‘greenhouse’ gas emissions. In response, these sinks have been labelled as ‘Blue Carbon, a rhetorical tool to distinguish them from terrestrial and ocean sinks, and the different approaches they would require for conservation. However, there are a number of knowledge gaps, untested underlying assumptions, and measurement practicalities in assessing an accurate value of carbon sequestration and storage. Unless these are addressed, then the push for seagrass and mangroves to be included within the carbon-financing network may not be successful. This short communication discusses the limitations of the current blue carbon conceptual model, and provides recommendations for a more limited but robust submission of its present and future worth, required for carbon financing

Fish diversity and distribution in the seagrass-coral reef continuum at two sites off the western coast of Isla Bastimentos, Bocas del Toro, Panama

Coral reefs are the most diverse marine ecosystem and the largest biogenic structure on Earth. They serve as shelter for many reef fishes and are a food source for resident and visiting fish species. In the tropics, coral reefs are often in close proximity to seagrass beds and the two contiguous marine habitats are not only highly interconnected but also highly understudied. The seagrass-coral reef continuum offers a wide array of services to human society as well as to various life stages of reef fishes resulting in diel, temporal, or yearly migrations of fish between the two habitats. Tropical reef fish diversity, abundance, and evenness were measured in both habitats in the morning and afternoon to determine if any significant differences in results between habitats or times of day could be observed. Underwater video recordings were taken of 15 m transects in the seagrass bed and coral reef at two sites, one sheltered and one more exposed, off Isla Bastimentos, Bocas del Toro, Panama. The recordings were used in calculating fish diversity, abundance, and evenness and in surveying the benthic composition of the coral reef. Sixteen transects were recorded in each habitat at each time of day at each site and a total of 3587 fish were observed representing 14 different families and 32 different species. Site 1 had low live coral coverage and was composed of mainly hard open substrate while Site 2 was composed mainly of macroalgae and live coral. Ultimately, no significant differences were found between fish abundance or evenness however, significant differences were found in fish diversity between the seagrass bed and coral reef (P\u3c0.001, df=3493) as well as between the morning and the afternoon (P\u3c0.001, df=3454). Based on these results, it can be concluded that habitat and time of day play significant roles in fish diversity and even though fish abundance and evenness were not significantly different, they generally aligned with conclusions made in previous studies

The differential importance of deep and shallow seagrass to Nekton assemblages of The Great Barrier Reef

Seagrass meadows are an important habitat for a variety of animals, including ecologically and socioeconomically important species. Seagrass meadows are recognised as providing species with nursery grounds, and as a migratory pathway to adjacent habitats. Despite their recognised importance, little is known about the species assemblages that occupy seagrass meadows of different depths in the coastal zone. Understanding differences in the distribution of species in seagrass at different depths, and differences in species diversity, abundance, biomass, and size spectra, is important to fully appreciate both the ecological significance and economic importance of these seagrass meadows. Here, we assess differences in the assemblage characteristics of fish, crustacea, and cephalopods (collectively, nekton) between deep ( > 9 m; Halophila spinulosa dominant) and shallow water ( < 2 m; Halodule uninervis and/or Zostera muelleri dominant) seagrass meadows of the central Great Barrier Reef coast of Queensland, Australia. Nekton assemblage structure differed between deep and shallow seagrass. Deeper meadows were typified by juvenile emperors (e.g., Lethrinus genivittatus), hairfinned leatherjacket (Paramonacanthus japonicus) and rabbitfish (e.g., Siganus fuscescens) in both biomass per unit effort (BPUE) and catch per unit effort (CPUE), whereas shallow meadows were typified by the green tiger prawn (Penaeus semisulcatus) and pugnose ponyfish (Secutor insidiator) in both BPUE and CPUE. Both meadow depths were distinct in their nekton assemblage, particularly for socioeconomically important species, with 11 species unique to both shallow and deep meadows. However, both meadow depths also included juveniles of socioeconomically important species found in adjacent habitats as adults. The total nekton CPUE was not different between deep and shallow seagrass, but the BPUE and body mass of individual animals were greater in deep than shallow seagrass. Size spectra analysis indicated that in both deep and shallow meadows, smaller animals predominated, even more so than theoretically expected for size spectra. Our findings highlight the unique attributes of both shallow and deeper water seagrass meadows, and identify the distinct and critically important role of deep seagrass meadows within the Great Barrier Reef World Heritage Area (GBRWHA) as a habitat for small and juvenile species, including those of local fisheries value