Analysis of Submerged Aquatic Vegetation Resources across the Northern Gulf of Mexico: Communities and Biomass

Submerged aquatic vegetation (SAV) provides many critical ecosystem services, yet we lack basic information on SAV assemblages, biomass and diversity across expansive coasts such as the northern Gulf of Mexico (nGoM). This research investigated SAV along the nGoM from 2013-2015 examining (1) inter-annual variation in SAV assemblages and biomass across salinity zones and gulf coast eco-regions (Texas Mid-Coast, Texas/LA Chenier Plain, Louisiana Delta, MS/AL), (2) intra-annual variation in SAV assemblages and biomass across salinity zones, (3) response of two species, Ruppia maritima and Myriophyllum spicatum, to salinity and light regimes, and (4) estimated organic carbon stock and storage of SAV habitat soils across salinity zones. Coast wide, there was no variation among years, but significant differences in biomass and diversity within zones and regions were observed. Specifically, fresh zones and the Louisiana delta region had higher species diversity and contained more biomass than other zones and regions. Intra-annually, there were significant differences in SAV biomass and assemblages by salinity zone and month. Fresh/ intermediate zones contained more species and biomass than brackish/saline zones, and biomass was higher in summer months than winter months. Competitive relationships between co-occurring species were examined using M. spicatum and R. maritima growth response, under different salinity and light regimes. M. spicatum growth decreased with increasing salinity, while R. maritima growth was not impacted. R. maritima was also not impacted by light, while M. spicatum growth increased in high light. We observed strong competitive interactions; both species decreased in mixture and under no conditions was production in mixtures greater than monocultures. We estimated organic carbon stocks (Corg) within Mississippi River Delta Plain (MRDP) SAV habitat, out to the Chandeleur Islands, and found that MRDP SAV Corg did not differ across salinity zones, but was greater than Chandeleur SAV Corg. MRDP SAV habitat (159,609 ha) contains greater than 3.2 * 107 Mg of Corg, representing an unaccounted for reservoir of “blue carbon,” particularly when extrapolated across the Gulf Coast. These new data provide a better understanding of factors controlling SAV spatial distribution, temporal variation and ecosystem services, which helps managers prepare for coastal changes

Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm.publishedVersio

The implications of nutrient loading on deltaic wetlands

The current debate in the scientific community (and by default the political community) regarding the restoration of coastal Louisiana includes a discussion on the impact of nutrients on the production of belowground biomass. Some research indicates that belowground biomass may decrease with nutrient enrichment. This may subject the receiving wetlands of freshwater diversions and wastewater effluent to increased erosion and wind throw, which could hinder storm buffering benefits. The objective was to utilize an ongoing mesocosm experiment to investigate the effects of nutrient loading from river diversions and treated wastewater on the (a) above- and belowground biomass production of wetland plants, (b) depth of root foraging activity, (c) overall effect on root to shoot ratio (R:S) and (d) soil elevation. The water quality experiment was set up as a completely randomized 2*2*3*4 factorial design. Four types of water quality (fresh water, fresh water with nutrients (90 g N m-2 yr -1), 3 ppt and 6 ppt) were crossed with three types of wetland hydrology (mesic, permanently flooded and constant throughput), sediment addition (yes, no) and a simulated hurricane (yes, no). After 5 years of growth, root to shoot ratio decreased (F=16.92,p30 cm) over the other water quality treatments (F=16.44,p) nitrogen dosing experiment was set up as a completely randomized 2*6 factorial design. The two tree species were crossed with six loading rates of fertilizer (0, 10, 50, 100, 200, and 400 g N m-2 yr-1). After two growing seasons, nitrogen loading had the strongest effect on aboveground biomass (F=18.77,p< 0.001), but also significantly affected root to shoot ratio (F=2.41,p=0.004) and belowground biomass (F=2.30,p=0.049). Tree species differed in root to shoot allocation (F=7.66,p=0.006) and aboveground biomass (F=10.43,p=0.002), but not belowground biomass. Finally, wood density increased for both species from 0-100 g N m-2 yr-1(F=3.38,p=0.007), then decreased for baldcypress, but not for water tupelo. The results of these experiments should be used to promote beneficial use of river diversions and treated wastewater to restore the wetlands of coastal Louisiana

Decline of the Maurepas Swamp, Pontchartrain Basin, Louisiana, and Approaches to Restoration

The Maurepas swamp is the second largest contiguous coastal forest in Louisiana but it is highly degraded due to subsidence, near permanent flooding, nutrient starvation, nutria herbivory, and saltwater intrusion. Observed tree mortality rates at study sites in the Maurepas swamp are very high (up to 100% tree mortality in 11 years) and basal area decreased with average salinities of &lt;1 ppt. Habitat classification, vegetation productivity and mortality, and surface elevation changes show a clear trajectory from stagnant, nearly permanently flooded forests with broken canopy to degraded forests with sparse baldcypress and dominated by herbaceous species and open water to open water habitat for most of the Maurepas swamp without introduction of fresh water to combat saltwater intrusion and stimulate productivity and accretion. Healthy forests in the Maurepas are receiving fresh water containing nutrients and sediments from urban areas, high quality river water, or secondarily treated municipal effluent. Currently, two proposed diversions into the swamp are via Hope Canal (57 m3·s−1) and Blind River (142 m3·s−1). These diversions would greatly benefit their immediate area but they are too small to influence the entire Maurepas sub-basin, especially in terms of accretion. A large diversion (&gt;1422 m3·s−1) is needed to deliver the adequate sediments to achieve high accretion rates and stimulate organic soil formation

Restoration and Management of a Degraded Baldcypress Swamp and Freshwater Marsh in Coastal Louisiana

The Central Wetlands Unit (CWU), covering 12,000 hectares in St. Bernard and Orleans Parishes, Louisiana, was once a healthy baldcypress–water tupelo swamp and fresh and low salinity marsh before construction of levees isolated the region from Mississippi River floodwaters. Construction of the Mississippi River Gulf Outlet (MRGO), which funneled saltwater inland from the Gulf of Mexico, resulted in a drastic ecosystem change and caused mortality of almost all trees and low salinity marsh, but closure of the MRGO has led to decreases in soil and surface water salinity. Currently, the area is open water, brackish marsh, and remnant baldcypress stands. We measured hydrology, soils, water and sediment chemistry, vegetation composition and productivity, accretion, and soil strength to determine relative health of the wetlands. Vegetation species richness is low and above- and belowground biomass is up to 50% lower than a healthy marsh. Soil strength and bulk density are low over much of the area. A baldcypress wetland remains near a stormwater pumping station that also has received treated municipal effluent for about four decades. Based on the current health of the CWU, three restoration approaches are recommended, including: (1) mineral sediment input to increase elevation and soil strength; (2) nutrient-rich fresh water to increase productivity and buffer salinity; and (3) planting of freshwater forests, along with fresh and low salinity herbaceous vegetation

Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm

Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm

Preoperative hemoglobin thresholds for survival equity in women and men

Anemia affects humans throughout life, and is linked to higher morbidity and mortality. Unclear is whether hemoglobin values are equivalent between women and men. This study evaluates the association of preoperative hemoglobin levels with in-hospital mortality and estimates thresholds for survival equity between men and women. All adult patients undergoing surgery between 2010 and 2019 from 14 German hospitals were included in the study. Thresholds for survival equity were determined with generalized additive models. In total, 842,130 patients with a median in-hospital follow-up time of 7 days were analyzed. During follow-up 20,370 deaths occurred. Preoperative hemoglobin stratified in-hospital mortality (log-rank test p &lt; 0.001) and was associated with mortality independently of demographic risk, surgical risk and health status. For each 1 g/dL reduction in preoperative hemoglobin, the odds of mortality increased by a factor of 1.22 (95% CI 1.21–1.23, p &lt; 0.001). A preoperative hemoglobin threshold of 10.5 g/dL reflected equivalent risk for both male and female patients. Hemoglobin levels below 10.5 g/dL had higher risk of mortality for women than for men. The findings from this study aid evidence-based thresholds, inform anemia management and promote equitable care, thus enhancing patient outcomes