Spatial and temporal patterns of salinity and temperature at an intertidal groundwater seep

摘要: Abstract Spatial and temporal patterns at an intertidal groundwater seep Cape Henlopen, Delaware, were characterized using a combination of pore water salinity sediment temperature measurements. Pore maps, both on small scale (resolution 0.1 m over 1.25 m 2 area) large (1–5 m 1710 m showed reduced salinities to as low one-sixth seawater strength in region 0–6 m from the beach slope break. In this region, there was substantial spatial variability all measured scales (0.1–90 m) alongshore. At −10 cm depth, ranged 6 24 less than 1 m horizontally. To further characterize discharge, we used novel probes during summer tides found temperatures much lower nearby sediment, 8–9 °C cooler −30 cm depth. Measurements time loggers that despite strong tidal diel forcing surficial temperatures, thermal anomalies due discharge persisted several-day sampling periods strongest −20 Over seasonal scale, monthly or near (by 3–4 °C) warmer winter 5–6 °C) compared non-seep location. ecological context, these differences are equivalent ∼250 km latitudinal shift northward ∼380 km southward winter, change important relation recognized biogeographical boundaries. Our results have implications for hydrological measurements made sandy sites like Henlopen. Existing methods such mass-balance geochemical tracer techniques integrate observed, but unable resolve small-scale may be biologically important. Seepage meters can capture meter will subject high inherent unless considered design replication. Intertidal profile point estimates complicated by varying boundary conditions interaction insolation exposure. addition methodological implications, observed suggests habitat envelope must when attempting interpret biological productivity, faunal abundance community composition benthic species living around seeps.