Benthic Resource Assessment Knights Key Resort Water Observation Platform Prepared for: Knights Key Resort 1 Knights Key Boulevard Marathon, Florida 33050 Prepared by: May 21, 2018 Knights Key Resort Observation Platform – Benthic Resource Assessment Introduction Knights Key Resort is located at 1 Knights Key Boulevard, marathon, Monroe County, Florida. The facility is currently undergoing re-development as a resort hotel. A water observation platform is proposed to provide guests viewing access to the waters of the Atlantic Ocean. The proposed water observation platform is a “T” design that extends from uplands out into shallow waters. The proposed walkway is 4’ in width and extends appx. 119’ over submerged lands and wetlands. The proposed terminal platform is 160 sf (16 x 10). The entire structure (walkway and terminus) is elevated a minimum of + 5.0 MHW and the decking is light-transmitting grating. The project was designed to comply with the U.S. Army Corps of Engineers/National Marine Fisheries Service “Construction Guidelines in Florida for Minor Piling- Supported Structures Constructed in or over Submerged Aquatic Vegetation”. Project plans prepared by Weiler Engineering were submitted as part of the application for the project and contain full construction details. An assessment of the benthic resources potentially impacted by the project expansion project was conducted on May 11, 2018. The objective of the benthic assessment was to assess and document living marine resources potentially impacted by the proposed project. In addition, a specific-purpose survey for corals was conducted to fulfill Florida Keys National Marine Sanctuary (FKNMS) requirements. Methods An in-water assessment of the project area was conducted on May 11, 2018 by scientific divers experienced in conducting resource assessments of benthic habitats found in the Florida Keys. Water clarity was excellent and water temperatures was 84 degrees F. Water depth in the survey area was shallow, never exceeding 24” in depth at the time of survey. The survey area included all areas of the proposed observation platform and the general vicinity. Due to the limited area, the entire survey area was evaluated. Using a tape, the proposed project was identified in the field and marked temporarily using small floats. The dominant benthic community within and adjacent to the survey area was assessed for benthic characteristics. The survey area was also inspected for the presence of corals or other unique benthic resources. Benthic communities were categorized into discrete habitats including hardbottom, seagrass, algae- dominated, and barren muck / sand. Where applicable, percent cover for observed benthic communities was categorized into discrete cover classifications by visual estimation using the following cover classes: Knights Key Resort Observation Platform – Benthic Resource Assessment Cover Classes Descriptors for Observed Benthic Communities Description Barren Sparse Moderate Dense Cover Class 0-1 % 1-25% 25-75% 75-100% The data recorded along the alignment of the walkway and terminal platform included the dominant habitat type present and dominant species present. This survey method provided a qualitative and quantitative assessment of the type and location of benthic resources found throughout the entire project footprint. Reference photographs representing dominant benthic species, examples of seagrass communities and other resources encountered, and other applicable reference photographs were taken (Attachment 1). Results The following survey sub-areas were identified and assessed for resources and project impacts (Table 1). Table 1. Benthic habitats in survey area. Distance refers to the baseline which starts at the wetland limits just landward of the mangrove limit. Survey Sub-Area Distance Notes Disturbed wetlands at the shoreline just upslope of Shoreline Wetland Zone 0’-10’ MHW. Habitat is barren with sandy course fill and weed wrack. This area is intertidal, being exposed at low tides. Intertidal Rocky Zone 10’ – 55’ Barren rock with limited filamentous algae and sparse macroalgae composed of scattered Batophora. Soft, mucky bottom with moderate to dense Soft bottom, muck and marl, with macroalgae composed of Halimeda, Laurencia, macroalgae dominant and trace 55’ – 95’ Acetabluaria, and Pennicillus. Seagrass (Halodule seagrass wrightii) present in trace amounts but not dominant. Soft bottom, muck and marl, with Soft, mucky bottom with moderate to dense seagrass 95’ to 120’ seagrass dominant composed of Halodule wrightii. Knights Key Resort Observation Platform – Benthic Resource Assessment Project Impacts The proposed project will have the following estimated impacts to identified benthic resources: • The project was designed to comply with the U.S. Army Corps of Engineers/National Marine Fisheries Service “Construction Guidelines in Florida for Minor Piling-Supported Structures Constructed in or over Submerged Aquatic Vegetation”. The structure is minimized in design, elevated, and the decking a light-transmitting grating. Shading impacts to the seagrass and macroalgae communities present in project footprint are minimal. • The proposed observation platform is for passive use only. There will be no mooring of vessels at the facility. • Impacts from the installation of 36 pilings is minimal, with only 32 sf of piling impact over the entire project including shoreline wetlands and submerged lands. • The proposed project will not impact mangroves. The proposed walkway is located in an existing barren area along the shoreline specifically to avoid mangrove impacts. • No hard or soft corals were identified in the survey area; no coral impacts are associated with the project. Knights Key Resort Observation Platform – Benthic Resource Assessment Attachment 1: Site Photographs Proposed observation platform showing alignment of walkway through an existing gap in the shoreline mangroves. Proposed observation platform showing rock intertidal zone and alignment of walkway through an existing gap in the shoreline mangroves. Knights Key Resort Observation Platform – Benthic Resource Assessment Proposed observation platform showing alignment of walkway through an existing gap in the shoreline mangroves and approximate location of the terminal platform just past (10’) the waterward edge of the shoreline mangrove fringe. Soft muck bottom with dense-cover macroalgae (Acetabularia, Batophora, Udotea, Pennicillus). Knights Key Resort Observation Platform – Benthic Resource Assessment Moderate-cover seagrass (Halodule wrightii) in deeper portions of the survey area. Dense-cover seagrass (Halodule wrightii) in deeper portions of the survey area. .