Monthly Kachemak Bay Report, February 2026
Summary
Air temperatures warmed from mid January to mid February 2026 to above the seasonal average. Inner Kachemak Bay waters remained colder (by up to one standard deviation, SD), and fresher (up to 1.5 SD) than normal throughout the water column. Conversely, outer bay/lower Cook Inlet waters were warmer and fresher than normal throughout the water column. Surface waters near the Homer Spit were unusually turbid, perhaps released from melting ice out of Mud Bay. A localized plume in the surface waters off the Homer Spit was unusually turbid for this location.
A complete set of up-to-date graphs can be found on this Google Drive: section plots and time sections (request access from martin.renner@noaa.gov).
Conditions
After an unusually cold start of the year, air temperatures in February were above the seasonal average. A thin cover of snow/ice covered much of Homer. Snow-water equivalent at the McNeil Canyon SNOTEL site was low (10th percentile). The intertidal of Mud Bay was covered in ice, but Homer Harbor was largely ice-free. Near the head of the bay, small floes of sea-ice, were seen, also less than in January. Hans, Kris, and Martin conducted the KBL monthly survey on 12 (extended AlongBay transect), and 17 February (across-bay transects T9 and T4). Sea state conditions on 12 February were moderate in lower Cook Inlet and glassy calm in the inner bay, and light to moderate on 17 February.
Physical oceanography
Temperature
Water temperatures during this survey ranged from a minimum of station 1.6 °C at station 9-10 (1 m depth), in the mid bay, to a maximum of 5.5 °C at station 6-3 (100 m depth) in lower Cook Inlet. Cook Inlet and outer bay waters were vertically mixed. A pronounced horizontal gradient from warmer, saltier Cook linlet waters to colder, fresher inner bay waters, was found near the Homer Spit. Inner bay waters showed stratification with a thin cold surface layer over warmer deep waters (Figure 2 (a), top-left panel).
Sea surface temperature data displayed similar patterns to last month, showing a gradient of warm water from the Gulf of Alaska, to the increasing cooler and shallower coastal waters of Cook Inlet (Figure 3).
Inner and much of outer Kachemak Bay water temperatures remained colder than normal (Figure 2, Figure 6, Figure 5). Lower Cook Inlet waters, however, were over one standard deviation (in this case 0.4 °C) warmer than the seasonal mean, from the surface down to depth (Figure 2 (a)). Surface waters of the Gulf of Alaska, as shown by satellite data, had warmed from colder than normal condition in January, again matching the warm-water anomaly of most of the North Pacific, (Figure 4).
For surface waters, satellite data showed that the rest of the Gulf of Alaska was also no longer colder than normal (Figure 4).
Salinity
Salinity values ranged from 29.2 PSU at station 9-4 (1m depth) near Homer Spit to 31.7 at station 6-3 (100m depth) in lower Cook Inlet. Inner bay waters were fresher than outer bay waters. The outer bay, and especially lower Cook Inlet, was more saline than the inner bay (Figure 2). Weak vertical stratification was evident in the inner bay. The water column in lower Cook Inlet, off Port Graham and Point Pogibshi was vertically mixed, as indicated by vertical contours in salinity and temperature (Figure 2 (a)). Along the inner bay, across mid-bay (T9) and into the eastern parts of the outer bay, a thin layer (~10-20 m) of cold, fresh water was seen over warmer, more salty water at depth, indicating that there had been enough freshwater input to maintain vertical stratification despite cold temperatures (Figure 2).
Compared to the long-term means, much of the inner bay, including all of T9, was fresher than normal, in some areas by over 2 standard deviations (SD). Some deep waters of lower Cook Inlet, on the other hand, were over 1.5 SDs saltier than normal. Salinity at mid-bay stations was close to normal, after major anomaly fluctuations in 2025 (Figure 8).
Turbidity
Inner bay waters were slightly more turbid than outer bay waters. Visually, we noticed high surface turbidity, off the Homer Spit. This was also noted by the turbidity sensor, recording unusually high turbidity of 2.5 SD more than normal along T9 off Homer Spit (Figure 2 (b)), which was also the highest turbidity measured anywhere during this survey. This pattern was consistent with the source of the turbidity coming from sediments carried in melting ice originating in Mud Bay.
Biological conditions
Phytoplankton
Chlorophyll concentrations were low throughout Kachemak Bay, as expected for February, and were near or below the long-term mean (Figure 2, Figure 9). There were pockets of elevated chlorophyll concentrations near the surface, however (Figure 2 (a)), corresponding with elevated O~2 saturation at about 15 m, indicating an onset of primary production (Figure 2).
Wildlife
Two harbor seals were seen off Bear Cove. About 65 Steller sea lions were seen on Flat Island. Birds of note included a yellow-billed loon off Bear Cove. Common murres and marbled murrelets started to return to the inner bay.
Mailing list
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