Why are modern techniques implemented in fisheries?

The angle between the tangents drawn from the point $(1,4)$ to the parabola $y^2=4x$ is

Calculate the heat of combustion (in $kJ$) of methane from the following data:
$(I)$ $C_{(graphite)} + 2H_{2(g)} \rightarrow CH_{4(g)} \quad \Delta H = -74.8 \ kJ$
$(II)$ $C_{(graphite)} + O_{2(g)} \rightarrow CO_{2(g)} \quad \Delta H = -393.5 \ kJ$
$(III)$ $H_{2(g)} + 1/2 O_{2(g)} \rightarrow H_2O_{(l)} \quad \Delta H = -286.2 \ kJ$

In the following compounds,the order of acidity is:
$(I)$ Phenol
$(II)$ $p$-Cresol ($4$-methylphenol)
$(III)$ $m$-Nitrophenol
$(IV)$ $p$-Nitrophenol

On combustion of $Li$,$Na$,and $K$ in excess of air,the major oxides formed,respectively,are:

Consider the following statements regarding the major pigments and stored food in the different groups of algae and select the correct option.
$I.$ In Chlorophyceae, the stored food material is starch and the major pigments are chlorophyll-$a$ and chlorophyll-$b$.
$II.$ In Phaeophyceae, laminarin is the stored food and major pigments are chlorophyll-$a$ and chlorophyll-$c$.
$III.$ In Rhodophyceae, floridean starch is the stored food and major pigments are chlorophyll-$a$, $d$ and phycoerythrin.