Eelgrass Distribution in the Great Bay Estuary and Piscataqua River for 2013

Eelgrass distribution and cover in Great Bay, Little Bay, and the Piscataqua River Estuary were mapped from aerial photography acquired on August 24, 2013. The total area of eelgrass beds with 10% or greater cover was 1683.4 acres. The largest concentration of eelgrass was found in Great Bay with lesser amounts in the vicinity of Portsmouth Harbor. Comparisons to previous years are not made here

Eelgrass Distribution in the Great Bay Estuary and Piscataqua River for 2017

Eelgrass distribution in Great Bay, Little Bay, and the Piscataqua River Estuary was mapped from aerial photography acquired on August 24, 2017. The total area of eelgrass beds with 10% or greater cover and a polygon area equal to or greater than 100 square meters was 625.9 hectares or 1546.7 acres. Eelgrass polygons were coded for Assessment Zone location and the results reported for each zone. The largest concentration of eelgrass was found in Great Bay with lesser amounts in the vicinity of Portsmouth Harbor. The total area of eelgrass beds with 10% or greater cover and a polygon area equal to or greater than 100 square meters has decreased by 142 acres which is approximately an 8.5% decrease from the previous year

Eelgrass Distribution in the Great Bay Estuary and Piscataqua River for 2016

Eelgrass distribution in Great Bay, Little Bay, and the Piscataqua River Estuary were mapped from aerial photography acquired on August 5, 2016. The total area of eelgrass beds with 10% or greater cover and a polygon area equal to or greater than 100 square meters was 683.42 hectares or 1688.71 acres. Eelgrass polygons were coded for Assessment Zone location and the results reported in Table 1.The largest concentration of eelgrass was found in Great Bay with lesser amounts in the vicinity of Portsmouth Harbor. The total area of eelgrass was nearly identical to that mapped in 2013 though there were variations in distribution

The ACS Nearby Galaxy Survey Treasury VI. The Ancient Star Forming disk of NGC 404

We present HST/WFPC2 observations across the disk of the nearby isolated dwarf S0 galaxy NGC 404, which hosts an extended gas disk. Our deepest field reaches the red clump and main-sequence stars with ages <500 Myr. Although we detect trace amounts of star formation at times more recent than 10 Gyr for all fields, the proportion of red giant stars to asymptotic giants and main sequence stars suggests that the disk is dominated by an ancient (>10 Gyr) population. Detailed modeling of the color-magnitude diagram suggests that ~70% of the stellar mass in the NGC 404 disk formed by z~2 (10 Gyr ago) and at least ~90% formed prior to z~1 (8 Gyr ago). These results indicate that the stellar populations of the NGC 404 disk are on average significantly older than those of other nearby disk galaxies, suggesting that early and late type disks may have different long-term evolutionary histories, not simply differences in their recent star formation rates. Comparisons of the spatial distribution of the young stellar mass and FUV emission in GALEX images show that the brightest FUV regions contain the youngest stars, but that some young stars (<160 Myr) lie outside of these regions. FUV luminosity appears to be strongly affected by both age and stellar mass within individual regions. Finally, we use our measurements to infer the relationship between the star formation rate and the gas density of the disk at previous epochs. We find that most of the history of the NGC 404 disk is consistent with star formation that has decreased with the gas density according to the Schmidt law. However, 0.5-1 Gyr ago, the star formation rate was unusually low for the inferred gas density, consistent with the possibility that there was a gas accretion event that reignited star formation ~0.5 Gyr ago. Such an event could explain why this S0 galaxy hosts an extended gas disk.Comment: 28 pages, 20 figures, 1 table, accepted for publication in Ap

Update on a Continuing Saga: Eelgrass and Green Crabs in Casco Bay, Maine (Poster)

https://digitalcommons.usm.maine.edu/cbep-graphics-maps-posters/1035/thumbnail.jp