Getting started with environmental cost accounting

Proactive corporations have been looking at methods to determine the real costs of doing business, including environmental costs using environmental cost accounting (ECA) methodology. Many companies do not track or measure environmental costs and therefore do not know their true environmental costs. Unfortunately, conventional accounting practices rarely tease out environmental costs, and the costs associated with environmental compliance remain hidden in general overhead accounts. ECA can bring the world of business and the environment closer. When we have a better handle on environmental costs, we can use this information to better prioritize environmental projects, identify cost improvement projects, and allocate environmental costs to products. In this article we explore how some companies approach ECA and show how to initiate an ECA program.     

Effects of salinity on the clam <Emphasis Type="Italic">Chamelea gallina</Emphasis> haemocytes. Part II: Superoxide dismutase response

The effects of different salinity levels (28, 34 and 40‰) on functional responses of Chamelea gallina haemocytes were evaluated in a two part study dealing with modulations of immune parameters. This part (Part II) of the study was focused on the superoxide dismutase (SODs) activity and expression in haemocyte lysate and cell-free haemolymph. Results of this study established that the exposure of C. gallina specimens at 40‰ salinity provoked a decrease in Mn-SOD and Cu/Zn-SOD activities in haemocyte lysate suggesting a declining superoxide anion generation at the highest salinity tested. Expression of MnSOD was coherent with activity values, while Cu/ZnSOD showed two immunoreactive bands. The former corresponds to the cytosolic Cu/Zn-SOD (16 kDa) was not coherent with the enzyme activity and the second (28–30 kDa) probably attributed to EC-SOD. In cell-free haemolymph, Mn-SOD activity decrease and Cu/Zn-SOD activity increase at 40‰ were observed, likely due to EC-SOD contribution, strongly induced at the same salinity. After EC-SOD detection with two different antibody, we postulate that the EC-SOD like-protein band (29 kDa) may be constitute partly by EC-SOD and probably by Cu/Zn-SOD dimeric form not completely dissociated under reducing condition or a Cu/Zn-SOD degenerated but still recognized by antibody. The cell-free haemolymph increase of EC-SOD at high salinity values plays an important role in immune defence of C. gallina. According to the conclusion of Part I of this study, our data confirmed the destabilizing effect of 40‰ salinity on haemocyte functionality, while to 28‰ exposure, data don’t confirm its stressful action as instead stated by results of Part I. Further studies are necessary to clear up this discrepancy.     

Microalgal communities epibiontic on the marine hydroid <Emphasis Type="Italic">Eudendrium racemosum</Emphasis> in the Ligurian Sea during an annual cycle

The microalgal community associated with Eudendrium racemosum, a marine hydroid widely distributed in the Mediterranean Sea, was studied during an annual cycle, at monthly frequency, in a coastal station of the Ligurian Sea. Microalgae were represented mainly by diatoms, which exhibited higher abundance and biomass values between autumn and spring (max 46,752 cells mm⁻² and 1.94 μg C mm⁻², respectively), while during summer a significant decrease was observed (min 917 cells mm⁻² and 0.013 μg C mm⁻²). High levels of abundance of filamentous cyanobacteria were observed in summer. Spatial distribution of epibiontic microalgae showed a markedly increasing gradient from the basal to the apical part of hydroid colonies. Considering the growth forms of diatom communities, motile diatoms (mainly small naviculoid taxa) were the most abundant in all the periods. Adnate (Amphora and Cocconeis spp.) were distributed mainly in the basal and central part of hydroid colonies and showed two peaks (autumn and summer). Erect forms (mainly Tabularia tabulata, Licmophora spp., Cyclophora tenuis) were mainly distributed in the apical part of the colonies and showed their maximum densities in spring–summer. Tube-dwelling (Berkeleya rutilans, Parlibellus sp.) were observed at low densities throughout the study period, without any significant temporal or spatial variability. Comparing the microalgal communities on marine hydroid to those grown on mimic substrata placed in the sampling station during summer, significantly higher values of abundance were observed in the hydroid, suggesting that microalgae may benefit from the polyp catabolites. This fact was particularly evident for the adnate diatoms, whose temporal trend paralleled the cycle of hydroid host.     

Effects of salinity on the clam <Emphasis Type="Italic">Chamelea gallina</Emphasis>. Part I: alterations in immune responses

In the present study, the effects of differing salinities on some important functional responses of haemocytes from the clam, Chamelea gallina, were investigated. The animals were kept for 7 days at 28‰ (hyposalinity), 34‰ (control) and 40‰ salinity (hypersalinity), and total haemocyte count (THC), haemocyte volume, phagocytosis, lysozyme-like activity (in both haemocyte lysate and cell-free haemolymph) were measured. The survival-in-air test was also performed. Clams kept at 28‰ showed significantly increased THC with respect to animals kept at 34 and 40‰. The analysis of haemocyte size frequency distribution highlighted that in clams kept at 28‰ the haemocyte fraction of about 5 μm in diameter and 50–100 femtolitre in volume increased markedly. Conversely, in animals kept at 40‰ an increase was observed in the haemocyte fraction having about 8–10 μm diameter and 400–500 femtolitre volume. Higher phagocytic activity was recorded in haemocytes from control clams, with respect to that of clams kept at 28 and 34‰. Lysozyme-like activity in haemocyte lysate was shown to increase significantly in animals kept at 28‰ with respect to that of clams kept at 40‰, whereas enzyme activity in cell-free haemolymph from clams kept at 34‰ was significantly higher with respect to that of clams maintained at 40‰. A relationship between phagocytosis and lysozyme secretion is suggested. The resistance to air exposure of clams kept at 28 and 40‰ was shown to decrease significantly; LT₅₀ values fell from 7 days in clams kept at 34‰ to 4 and 5 days in those kept at 28 and 40‰, respectively. Results demonstrated that salinity values far from 34‰ affects the functional responses of haemocytes and reduce the resistance of clams to exposure to air.     

Toxicity attenuation of olive mill wastewater in soil slurries

Olive mill wastewaters are toxic for plants and microbes due to their high polyphenol content. We studied the effect of agricultural soil as a natural catalyst to promote polyphenol oxidation and polymerization, and in turn detoxify olive mill wastewaters. We show that model polyphenols are fully converted in soil slurries. Their products show no toxicity to the growth of a typical soil bacterium, Bacillus cereus, and reduced phytotoxicity in germination tests with English cress seeds. Those findings are promising for the sustainable treatment of olive wastewater in aerated soil slurries.     

Interaction between Fe-cyanide complex and humic acids

The fate of cyanides in soil is strongly influenced by the formation of Fe cyanides, which can interact with organic and inorganic colloids and precipitate as stable compounds. Scarce information is available on the capacity of humic acids to interact with cyano-complexes and thus affect the leaching and prevent the risk of contamination of watertable. Here we show that interaction between humic acids (HAs) and ferricyanide complex led to a formation of ferricyanide-humo micelles, and that the interaction did not imply changes in the original structure of ferricyanide complex.     

Ventilation or nest defense—parental care trade-offs in a fish with male care

Brood guarding animals face many critical trade-offs. Sand goby males (Pomatoschistus minutus) build nests with larger openings during low oxygen conditions, presumably to enhance ventilation. However, this may make the nest easier for egg predators to detect and harder for guarding males to defend. Manipulating oxygen level and predator presence (a small crab) for small and large males, we found support for a parental trade-off between fanning and nest defense. An increased fanning activity resulted in less time for guarding. Small males and males in low oxygen showed a higher fanning expenditure than large males and males in high oxygen, but surprisingly, filial cannibalism did not differ between these groups. Males built larger nest openings in low than high oxygen. However, males in both high and low oxygen treatments reduced their nest opening size in the presence of a predator, again indicating an important trade-off between ventilation and nest defense.     

Do male barn swallows (<Emphasis Type="Italic">Hirundo rustica</Emphasis>) experience a trade-off between the expression of multiple sexual signals?

Some sexual selection models envisage exaggerated male secondary sexual characters to be costly and therefore reliable indicators of the quality of potential mates to choosy females. If male secondary sexual characters have a natural selection cost, they may be linked to each other by reciprocally constraining relationships that would prevent individual males from increasing their level of multiple signaling. Barn swallow (Hirundo rustica) males have at least two costly signals relevant to socio-sexual interactions: tail length and song. Under the hypothesis that a trade-off exists between male signals, we manipulated the maintenance cost of tail ornaments to test whether this reduced the quantity and quality of song, a condition-dependent, phenotypically plastic signal. Contrary to our expectation, tail elongation had no effect on singing activity and song complexity. However, tail-elongated males produced songs with longer terminal parts ('rattles'). Long rattles are associated with highly competitive social contexts and high circulating levels of testosterone, suggesting that tail-elongated males were more frequently involved in either male-male aggressive or inter-sexual interactions. Therefore, this study shows that males are not displaying multiple signals at the maximum possible level, implying that this system is open to unreliable communication. However, long-term trade-offs between signal expression and viability may prevent males from displaying both signals at higher rates.Communicated by: M. Webster