Seagrass habitats of Bocas del Toro, Panama · Seagrass meadows within the Bocas del Toro...
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MDL alassia testudinum is the dominant seagrass, and the leaves are frequently coated with a fine layer of sediment Runoff, canals, and rivers deposit high sediment and nutrient loads in these seagrass habitats Decomposing mangrove and marsh leaves and branches result in high organic content of sediments, which are high water content ‘oozy’ mud Fine sediments are frequently resuspended, resulting in turbid water with low light penetration MDL e maximum depth to which alassia grows is generally between 1.5 and 2.5 m in these habitats Wetland-influenced habitats Typical shoreline alassia testudinum Dried sediment Wetland-influenced habitats are characterized by highly organic ‘oozy’ sediments and contain alassia testudinum. ese meadows have a shoot density of 246 ± 66 shoots m² and the maximum depth limit to which the seagrass grows is typically 1.5–2.5 m deep. Resuspension of the fine sediments is common, reducing light penetration through the water. Although macroalgal epiphytes are not common on the seagrass leaves, some seagrass leaves are covered in diatoms and leaves are commonly coated with a fine sediment layer. Seagrass habitats of Bocas del Toro, Panama A balance between river, mangrove and coral influences Seagrass meadows within the Bocas del Toro archipelago, Panama, are strongly influenced by their proximity to coral reefs, mangrove forests, and coastal rivers. Reef, mangrove, and river inputs influence sediment composition and water clarity, two of the most important factors responsible for the occurrence and abundance of seagrass meadows. Large volumes of silicoclastic sediment (silica sand) are deposited by the large rivers, high organic matter comes from the mangrove forests as well as associated wetlands, and eroding coral produces coarse carbonate sediment. An important modifier of these habitats and determinant of the type of seagrass that will survive is the amount of protection from water motion. e resulting seagrass communities within the Bocas del Toro archipelago can be divided into the following five categories, each linked to a dominant influence: wetland, river, mangrove, coral, and ocean swell. Seagrass observations: Tim Carruthers, Gabriel Jacome, and Penny Barnes Georeferencing and maps: Lisa Addington and Rachel Collin For further information on Bocas del Toro seagrass habitats, email: [email protected] on Bocas del Toro Research Station, email: [email protected] on conceptual diagrams, visit: http://ian.umces.edu Smithsonian Tropical Research Institute Bocas del Toro Research Station MDL alassia testudinum is the dominant seagrass, growing in a narrow band, with a maximum depth of 2–3m. Small patches of Halodule wrightii may grow inshore Groundwater and river inputs of freshwater result in frequent stratification of the water, with cold, fresh water on the surface Rainforest occurs along the shore of these habitats, dominated by the abundant coarse siliciclastic sediment (river sand) Turbid river water and frequent resuspension result in high sediment loads suspended in the water column River-influenced habitats Typical shoreline alassia testudinum Dried sediment River influenced habitats have coarse siliciclastic sediment (river sand), and while predominantly containing alassia testudinum, may also have small patches of Halodule wrightii in shallower areas, near to freshwater inputs. e coastline is either mangrove, or more commonly, forest coming to the back of a sandy beach. Shoot density of alassia testudinum is 410 ± 60 shoots m-2 and the maximum depth to which alassia grows in these habitats is 2–3 m. Mangroves protect these habitats from water motion Deep, mostly carbonate sand, and low water motion result in high light penetration with alassia growing to 6–9 m alassia testudinum is the dominant seagrass, however Halophila decipiens grows at the shallow and deep extremes of the meadows Bioturbation by Callianassa sp. shrimps is common in deep sand areas In from mangrove islets, coral (Agaricia sp. and Porites sp.) and sponges are common amongst seagrass In these calm habitats, pelagic and benthic (Cassiopea sp.) jellyfish are common Freshwater flows from the mangroves both on shore and small mangrove islands, often resulting in a fresh surface layer overlying more saline water Rhizophora mangle Mangrove-influenced habitats Typical shoreline alassia testudinum Dried sediment Mangrove-influenced seagrass habitats have deep sediment, often fine sand with high organic content, however they contain variable carbonate content from various sources. Characteristically, these meadows are highly protected from water movement. Limited coral colonies occur, but calcareous macroalgae such as Halimeda sp. and Penicillus sp. are common and these sites contain abundant sponges, ctenophores, and jellyfish, particularly Cassiopea sp. e dominant seagrass in this habitat is alassia testudinum however, at some sites, Halophila decipiens occurs at the shallow or deep extremes of the meadow. alassia shoot density is 299 ± 24 shoots m² and grows down to 6–9 m. 10 pt Freshwater from surface and groundwater flows through shallow reef lagoons Reef lagoons often contain very fine carbonate sand which is easily resuspended by wind, giving the water a milky-white appearance alassia occurrence outside of reef lagoons is restricted by wind-driven water motion alassia testudinum within the shallow water and thin (<2 cm) sand is often sparse and stunted e reef lagoon has a diversity of hard and soft corals as well as macroalgae such as Halimeda sp. Shore vegetation adjacent to these habitats can be rainforest or mangrove Coral-influenced habitats Typical lagoon alassia testudinum Dried sediment Reef-influenced habitats contain a diversity of hard and soft corals as well as invertebrates and macroalgae. Within the reef lagoon, the water is typically shallow (<1 m) with only a thin veneer of sand (<2 cm) over broken coral rubble. e seagrass is often stunted. alassia testudinum (280 ± 31 shoots m²) occurs further from the mainland in reef lagoons with slightly deeper sand, and Syringodium filiforme also occurs. On the outside of these lagoons, seagrass is restricted by wind-driven water movement, although where calm enough, water clarity is often high and seagrass grows down to 4–6 m. 82°15' W 82° W 9° N 9°15' N 0 5 10 km 200 m 100 m 50 m 10 m 10 m 10 m 50 m Laguna de Chiriqui Bahia Almirante Caribbean Sea Isla Colon Isla San Cristobal Isla Popa Cayo Agua Isla Bastimentos Peninsula Valiente Mangrove Ocean swell Coral River Wetland Habitat type N Locations of the five seagrass habitats throughout the Bocas del Toro archipelago. e watersheds are indicated in yellow and green, and coral reefs in golden brown. Shore vegetation adjacent to these habitats is generally rainforest, with either beach or granite boulders along the waterline Large swell waves limit seagrass occurrence with ‘blowouts’ common in this coarse calcareous sand alassia testudinum and Syringodium filiforme co-occur, and macroalgal epiphtes on Syringodium and calcarious encrusting epiphytes on alassia are common Macroalgae such as Penicillus sp. and Halimeda sp. grow abundantly in these seagrass meadows MDL MDL Frequent ocean flushing ensures high water clarity and seagrass in these habitats grows down to 7–10 m Ocean swell-influenced habitats Typical shoreline alassia testudinum, Syringodium filiforme Dried sediment Ocean swell-influenced habitats contain both alassia testudinum and Syringodium filiforme, often with abundant macroalgae such as Halimeda sp. and Penicillus sp. throughout the meadow. Sediment is usually highly calcareous coarse sand. Meadows are often patchy due to erosion of sand to form ‘blowouts’ which migrate through the meadows, and alassia density is approximately 218 ± 75 shoots m². High oceanic water exchange results in clear water and seagrass grows down to 7–10 m. MEXICO PANAMA EL SALVADOR GUATEMALA BELIZE HONDURAS NICARAGUA COSTA RICA JAMAICA Bocas del Toro HAITI DOM. REP. COLOMBIA VENEZUELA PUERTO RICO Caribbean Sea Pacific Ocean 10° N 5° N 15° N 20° N 65° W 70° W 75° W 80° W 85° W 90° W 95° W 500 km 0 500 miles 0
Transcript of Seagrass habitats of Bocas del Toro, Panama · Seagrass meadows within the Bocas del Toro...
MDL
�alassia testudinum is thedominant seagrass, and the leaves arefrequently coated with a fine layer of sediment
Runoff, canals, and rivers deposithigh sediment and nutrient loads in these seagrass habitats
Decomposing mangrove and marsh leavesand branches result in high organic content of sediments, which are high water content ‘oozy’ mud
Fine sediments are frequentlyresuspended, resulting in turbidwater with low light penetration
MDL�e maximum depth to which �alassia grows is generally between 1.5 and 2.5 min these habitats
Wetland-influenced habitats
Typical shoreline
�alassia testudinum
Dried sediment
Wetland-influenced habitats are characterized by highly organic ‘oozy’ sediments and contain �alassia testudinum. �ese meadows have a shoot density of 246 ± 66 shoots m² and the maximum depth limit to which the seagrass grows is typically 1.5–2.5 m deep. Resuspension of the fine sediments is common, reducing light penetration through the water. Although macroalgal epiphytes are not common on the seagrass leaves, some seagrass leaves are covered in diatoms and leaves are commonly coated with a fine sediment layer.
Seagrass habitats of Bocas del Toro, PanamaA balance between river, mangrove and coral influencesSeagrass meadows within the Bocas del Toro archipelago, Panama, are strongly influenced by their proximity to coral reefs, mangrove forests, and coastal rivers. Reef, mangrove, and river inputs influence sediment composition and water clarity, two of the most important factors responsible for the occurrence and abundance of seagrass meadows. Large volumes of silicoclastic sediment (silica sand) are deposited by the large rivers, high organic matter comes from the mangrove forests as well as associated wetlands, and eroding coral produces coarse carbonate sediment. An important modifier of these habitats and determinant of the type of seagrass that will survive is the amount of protection from water motion. �e resulting seagrass communities within the Bocas del Toro archipelago can be divided into the following five categories, each linked to a dominant influence: wetland, river, mangrove, coral, and ocean swell.
Seagrass observations: Tim Carruthers, Gabriel Jacome, and Penny BarnesGeoreferencing and maps: Lisa Addington and Rachel Collin
For further information on Bocas del Toro seagrass habitats, email: [email protected] on Bocas del Toro Research Station, email: [email protected] on conceptual diagrams, visit: http://ian.umces.edu
Smithsonian Tropical Research InstituteBocas del Toro Research Station
MDL
�alassia testudinum is the dominantseagrass, growing in a narrow band, with a maximum depth of 2–3m. Small patches ofHalodule wrightii may grow inshore
Groundwater and river inputsof freshwater result in frequentstratification of the water, with cold,fresh water on the surface
Rainforest occurs along theshore of these habitats,dominated by the abundantcoarse siliciclastic sediment (river sand)
Turbid river water and frequentresuspension result in high sedimentloads suspended in the water column
River-influenced habitats
Typical shoreline
�alassia testudinum
Dried sediment
River influenced habitats have coarse siliciclastic sediment (river sand), and while predominantly containing �alassia testudinum, may also have small patches of Halodule wrightii in shallower areas, near to freshwater inputs. �e coastline is either mangrove, or more commonly, forest coming to the back of a sandy beach. Shoot density of �alassia testudinum is 410 ± 60 shoots m-2 and the maximum depth to which �alassia grows in these habitats is 2–3 m.
Mangroves protect thesehabitats from water motion
Deep, mostly carbonate sand, and low water motion result in high light penetration with �alassia growing to 6–9 m
�alassia testudinum is the dominantseagrass, however Halophila decipiensgrows at the shallow and deep extremesof the meadows
Bioturbation by Callianassa sp. shrimps is common in deep sand areas
In from mangrove islets,coral (Agaricia sp. and Porites sp.) and sponges are common amongst seagrass
In these calm habitats, pelagic and benthic(Cassiopea sp.) jellyfish are common
Freshwater flows from the mangroves both on shore andsmall mangrove islands, often resulting in a fresh surface layeroverlying more saline water
Rhizophora mangle
Mangrove-influenced habitats
Typical shoreline
�alassia testudinum
Dried sediment
Mangrove-influenced seagrass habitats have deep sediment, often fine sand with high organic content, however they contain variable carbonate content from various sources. Characteristically, these meadows are highly protected from water movement. Limited coral colonies occur, but calcareous macroalgae such as Halimeda sp. and Penicillus sp. are common and these sites contain abundant sponges, ctenophores, and jellyfish, particularly Cassiopea sp. �e dominant seagrass in this habitat is �alassia testudinum however, at some sites, Halophila decipiens occurs at the shallow or deep extremes of the meadow. �alassia shoot density is 299 ± 24 shoots m² and grows down to 6–9 m.
10 pt
Freshwater from surface and groundwaterflows through shallow reef lagoons
Reef lagoons often contain very finecarbonate sand which is easilyresuspended by wind, giving thewater a milky-white appearance
�alassia occurrence outside of reef lagoons is restricted by wind-drivenwater motion
�alassia testudinum withinthe shallow water and thin (<2 cm)sand is often sparse and stunted
�e reef lagoon has a diversity ofhard and soft corals as well asmacroalgae such as Halimeda sp.
Shore vegetation adjacent to thesehabitats can be rainforest or mangrove
Coral-influenced habitats
Typical lagoon
�alassia testudinum
Dried sediment
Reef-influenced habitats contain a diversity of hard and soft corals as well as invertebrates and macroalgae. Within the reef lagoon, the water is typically shallow (<1 m) with only a thin veneer of sand (<2 cm) over broken coral rubble. �e seagrass is often stunted. �alassia testudinum (280 ± 31 shoots m²) occurs further from the mainland in reef lagoons with slightly deeper sand, and Syringodium filiforme also occurs. On the outside of these lagoons, seagrass is restricted by wind-driven water movement, although where calm enough, water clarity is often high and seagrass grows down to 4–6 m.
82°15' W 82° W
9° N
9°15' N
0 5 10 km
200 m100 m
50 m 10 m
10 m
10 m
50 m
Laguna de Chiriqui
BahiaAlmirante
Caribbean Sea
Isla Colon
IslaSan
Cristobal
Isla Popa Cayo Agua
IslaBastimentos
Peninsula Valiente
MangroveOcean swellCoralRiverWetland
Habitat type
N
Locations of the five seagrass habitats throughout the Bocas del Toro archipelago. �e watersheds are indicated in yellow and green, and coral reefs in golden brown.
Shore vegetation adjacent to these habitats is generally rainforest, with either beach or granite boulders alongthe waterline
Large swell waveslimit seagrass occurrencewith ‘blowouts’ common in thiscoarse calcareous sand
�alassia testudinum and Syringodiumfiliforme co-occur, and macroalgal epiphtes on Syringodium and calcarious encrusting epiphytes on �alassia are common
Macroalgae such as Penicillus sp. and Halimeda sp. grow abundantly inthese seagrass meadows
MDL
MDLFrequent ocean flushing ensures high water clarityand seagrass in these habitats grows down to 7–10 m
Ocean swell-influenced habitats
Typical shoreline
�alassia testudinum, Syringodium filiforme
Dried sediment
Ocean swell-influenced habitats contain both �alassia testudinum and Syringodium filiforme, often with abundant macroalgae such as Halimeda sp. and Penicillus sp. throughout the meadow. Sediment is usually highly calcareous coarse sand. Meadows are often patchy due to erosion of sand to form ‘blowouts’ which migrate through the meadows, and �alassia density is approximately 218 ± 75 shoots m². High oceanic water exchange results in clear water and seagrass grows down to 7–10 m.
MEXICO
PANAMA
EL SALVADOR
GUATEMALA
BELIZE
HONDURAS
NICARAGUA
COSTARICA
JAMAICA
Bocasdel Toro
HAITI
DOM. REP.
COLOMBIA
VENEZUELA
PUERTORICO
CaribbeanSea
PacificOcean
10° N
5° N
15° N
20° N
65° W70° W75° W80° W85° W90° W95° W
500 km0
500 miles0
